Moderate Cosmetic Ingredient NOAEL Data SCCS/CIR Reviewed Sensitization Data

1-Naphthol

Also known as: 1-naphthalenol, NAPHTHOL, CI Oxidation Base 33, EINECS 201-969-4, UNII-2A71EAQ389 (+6 more)

INCI: 1-NAPHTHOL

1-Naphthol (CAS 90-15-3) is a cosmetic cosmetic ingredient functioning as Oxidative hair dye intermediate (coupler). NOAEL 120 mg/kg bw/day (cross-referenced against ToxValDB ECHA IUCLID); EU Regulation 1223/2009 status: restricted, max 2.0%; 1 safety opinion reviewed (cir). Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in industrial chemical safety and pharmaceutical data.

View industrial chemical safety profile for CAS 90-15-3 →

Auto-generated CPSR Part A draft with source citations
CAS Number
90-15-3
View industrial chemical safety profile →
Function
Oxidative hair dye intermediate (coupler)
Safety Rating
MODERATE

Chemistry & Identifiers

Formula
C10H8O
MW
144.17 g/mol
EC Number
201-969-4
PubChem CID
7005
IUPAC Name
naphthalen-1-ol
InChIKey
KJCVRFUGPWSIIH-UHFFFAOYSA-N
ChEBI: CHEBI:10319 UNII: 2A71EAQ389 Wikidata: Q408876

Regulatory Status

EU EU Status restricted
EU Max Conc. 2.0%
US US Status permitted
US Notes Permitted as coal-tar hair dye with caution statement (21 CFR §73.2190); patch test warning required

For full compliance data across multiple jurisdictions, use the Substance Compliance tool.

Safety Data

Margin of Safety, dermal absorption, and sensitization profile summaries for 1-Naphthol.

Calculate MoS for your specific formulation with the MoS Calculator.

Toxicological Studies

10 study endpoints found for 1-Naphthol. NOAEL (No Observed Adverse Effect Level) values are used to calculate the Margin of Safety per SCCS methodology.

Endpoint Value Route Species Study Type Source
NOAEL 20 mg/kg bw/day oral rat Developmental COSMOS_DB
NOAEL =20 mg/kg bw/day - rat developmental toxicity SCCNFP_vision_codex
NOAEL =20 mg/kg oral rat dermal absorption SCCNFP_vision_codex
NOAEL =20 mg/kg bw/day - rat developmental toxicity SCCNFP_vision_codex
NOAEL =20 mg/kg oral rat dermal absorption SCCNFP_vision_codex
NOAEL =20 mg/kg bw/day - rat developmental toxicity SCCNFP_vision_codex
NOAEL =20 mg/kg oral rat dermal absorption SCCNFP_vision_codex
NOAEL =20 mg/kg bw/day - rat developmental toxicity SCCNFP_vision_codex
NOAEL =20 mg/kg oral rat dermal absorption SCCNFP_vision_codex
NOAEL =100 mg/kg bw/day - rat developmental toxicity SCCNFP_vision_codex

Safety Opinions

Official safety assessments from the Scientific Committee on Consumer Safety (SCCS) and Cosmetic Ingredient Review (CIR).

cir
Verdict: unknown

Pre-Calculated Safety Assessment

Pre-calculated NOAEL → SED → MoS audit trail for 1-Naphthol across SCCS product categories, with measured dermal absorption where available.

Sensitization Profile

Contact sensitization data for 1-Naphthol based on clinical patch test studies and IFRA standards.

Sensitization Rate
low
Allergen Class
dye
EU Allergen Listed
no
Patch Test Positive Rate
0.3%
Cross-reactivity Group
para-amino-group
Reaction Type
contact-dermatitis

Source: IVDK; NACDG; ESSCA

EU CLP Annex VI Harmonized Classification

Legally binding harmonized classification per Regulation (EC) No 1272/2008 (CLP) Annex VI.

Signal Word
Danger
Pictograms
Harmful / IrritantCorrosive
Hazard Class and Category
Acute Tox. 4 *; Acute Tox. 4 *; STOT SE 3; Skin Irrit. 2; Eye Dam. 1
Hazard Statements
  • H312 Harmful in contact with skin
  • H302 Harmful if swallowed
  • H335 May cause respiratory irritation
  • H315 Causes skin irritation
  • H318 Causes serious eye damage

Inserted via ATP: CLP00

Sensitization AOP Dashboard

Adverse Outcome Pathway data across 5 assays (DPRA, KeratinoSens, hCLAT, LLNA, NESIL) aggregated from public sources.

DPRA Cys %
45%
DPRA Lys %
14.9%
KeratinoSens IC50
541.003 µM
hCLAT CV75
57.2 µg/mL
LLNA EC3
1.3%
NESIL
325 µg/cm²
LLNA: Strong (1A) GHS: 1A

Source: LLNA: Gerberick et al. (2005); DPRA: Nukada et al. 2013 [DOI:10.1016/j.tiv.2012.11.006] | Natsch et al. 2013 [DOI:10.1002/jat.2868]; KS: Urbisch et al. 2015 [DOI:10.1016/j.yrtph.2014.12.008] | Natsch et al. 2013 [DOI:10.1002/jat.2868]; hCLAT: Ashikaga et al. 2010 [DOI:10.1177/026119291003800403]

ECHA REACH Registration

European Chemicals Agency REACH dossier and Substances of Very High Concern listing.

Registration Type
Full
Tonnage Band
100 - 1,000 tonnes
Substance Type
SUBSTANCE
SVHC Candidate
No
Hazard classification: Restricted (Annex XVII)

Expanded Jurisdictional Detail

Additional regulatory detail beyond the 7-jurisdiction summary: Saudi SFDA, Korea MFDS, ASEAN ACD, Japan/Korea, Brazil/India, and cross-jurisdictional restriction entries.

KR Korea MFDS Annex 2 (Restricted)
Category: Restricted. Max: 산화염모제에 2.0%. 기타 제품에는 사용금지
SA Saudi SFDA (III - Restricted)
Product type: Hair dye substance in oxidative hair dye products.
BRIN Brazil/India Cosmetics
Brazil: Restricted
India: Restricted
India: Restricted
Additional Jurisdictional Restrictions (4)
Jurisdiction Status Max % Product Type
CN permitted_hair_dye 2 Oxidative hair dye products
BR restricted 2 Oxidative hair dyes only; when combined with H2O2 max 1% in ready-to-use product
BR permitted_hair_dye 2 Oxidative hair dye; max 1% in ready-to-use with H2O2
ASEAN restricted 2% Oxidative hair dyes

Expanded Dermal Absorption Data

Cross-database dermal penetration: EPA Dryad physics-based, Roberts Mendeley permeation, and SCCS-aggregated measured values.

Roberts Skin Permeation (Mendeley 2022)
MW: 144.17
Log Kow: 2.840106094456758
Log Kp: -1.585026652029182
Log Jmax: -6.8063836584678326

Source: Roberts_Cheruvu_Mendeley_2022

Aggregated DA Values (3 records across 5 sources)
Type DA % Method Skin Model SCCS Ref
measured 4.0% in_vitro - SCCP/0125
measured 2.0% - - SCCP/0125
measured 65.0% - - SCCP/0125

Additional Ingredient Properties

2 property records from structured ingredient metadata.

allergen_detail
{"eu_allergen_listed": "no", "allergen_class": "dye", "cross_reactivity_group": "para-amino-group", "patch_test_frequency_pct": "0.3", "sensitization_rate": "low", "common_reaction_type": "contact-dermatitis", "ifra_restricted": "no", "source": "IVDK; NACDG; ESSCA"}
hair_dye
{"cas_number": "90-15-3", "ingredient_class": "oxidative_dye_coupler", "color_index_CI_number": "76605", "chemical_class": "naphtol", "molecular_weight_Da": "144.17", "color_result_on_hair": "Blue-violet modifier", "shade_range": "black", "primary_function": "coupler", "oxidative_dye_type": "coupler", "requires_developer": "yes", "permanence": "permanent", "wash_fastness_shampoos": "28-30", "oxida…

PubChem Annotations

Safety and regulatory annotations from PubChem (NCBI) aggregated sources.

Safety (1)
Carcinogen Classification
No indication of carcinogenicity to humans (not listed by IARC).
Source: Toxin and Toxin Target Database (T3DB)

Function Categories & List Membership

Cosmetic/Chemical Function Categories
Degradant/impurity Dye Intermediate
Regulatory List Membership (1)
EU CosIng Cosmetics Ingredient Database

Expert Verdict

Expert safety assessment and concern-level summary for 1-Naphthol.

Regulatory Flags

potential-allergen endocrine_disruptor eu_cosing_listed

NOAEL Studies Summary

View details ->

Public NOAEL study rows linked to 1-Naphthol by CAS number or substance name.

Studies
41
Lowest NOAEL
20
Highest NOAEL
400

Units vary across source rows: mg/kg bw/day, mg/kg bw, mg/kg

COSMOS_DB SCCS_vision_codex SCCNFP_vision_codex

Dermal Absorption

View details ->
Absorption % Method Vehicle
4.0% in_vitro -
2.0% - -
65.0% - -

Known Synonyms

1-naphthalenol NAPHTHOL CI Oxidation Base 33 EINECS 201-969-4 UNII-2A71EAQ389 Naphthol-1 Naphthyl-1-ol Tertral ERN alpha-Naphthol alpha-Naphthyl alcohol alpha-hydroxynaphthalene

Chemical Function

Dye Intermediate Degradant/impurity

Regulatory Lists

Europe; Personal care; restricted Europe; Personal care; restricted Arts and crafts/Office supplies - general arts and crafts supplies - arts and crafts paint; Europe Europe; Personal care - hair coloring detected; Europe; Personal care - hair coloring - hair color - professional detected; Europe; Personal care - hair coloring - hair color - professional detected; Europe; Personal care - hair coloring agricultural; animal_products; detected; Pesticides; residue agricultural; animal_products; detected; Pesticides; residue agricultural; detected; fruits_and_vegetables; Pesticides; residue agricultural; detected; fruits_and_vegetables; Pesticides; residue agricultural; detected; fruits_and_vegetables; Pesticides; residue agricultural; detected; fruits_and_vegetables; Pesticides; residue agricultural; animal_products; detected; Pesticides; residue agricultural; detected; fruits_and_vegetables; Pesticides; residue agricultural; detected; fruits_and_vegetables; Pesticides; residue agricultural; detected; fruits_and_vegetables; Pesticides; residue agricultural; detected; fruits_and_vegetables; Pesticides; residue

Australian Status

AICIS status: listed

Cross-Vertical Safety Context

Same-CAS public records found in pharmaceutical data.

SOURCE ChEMBL / DrugCentral / FAERS DB_PHARMA CAS match

Pharmaceutical Data

Same-CAS rows from the pharmaceutical spoke database.

Compound
1-NAPHTHOL
ChEMBL ID
CHEMBL122617
View full pharmaceutical profile →

Frequently Asked Questions

Is 1-Naphthol safe in cosmetics?

1-Naphthol has a safety rating of "MODERATE" in our database. EU status: restricted. US status: permitted. 10 toxicological study endpoint(s) are available in our database. This ingredient has been reviewed by cir.

Is 1-Naphthol allowed in the EU?

1-Naphthol EU regulatory status: restricted. Maximum allowed concentration: 2.0%. This is based on EU Regulation 1223/2009 and its amendments.

What does 1-Naphthol do in cosmetics?

1-Naphthol functions as: Oxidative hair dye intermediate (coupler). It is classified as a cosmetic ingredient in our database. CAS number: 90-15-3.

What is the NOAEL for 1-Naphthol?

The NOAEL (No Observed Adverse Effect Level) for 1-Naphthol is 20 mg/kg bw/day based on a Developmental study via oral route in rat. A total of 10 study endpoints are available. Source: COSMOS_DB.

Is 1-Naphthol used outside cosmetics?

1-Naphthol also appears in industrial chemical safety and pharmaceutical data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.

Does 1-Naphthol have different safety status in cosmetics vs industrial chemicals?

1-Naphthol is classified GHS Danger (H302, H311, H312, H315, H317, H318, H335, H400) in the chemicals database but is restricted in EU cosmetics at max 2.0%.

Compliance Tools

Check 1-Naphthol compliance across multiple jurisdictions:

Ingredient Decoder
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82 Allergen Checker
Check for EU declarable fragrance allergens
Substance Compliance
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MoS Calculator
Calculate Margin of Safety using SCCS methodology
Heavy Metal Limits
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