NOAEL Data REACH Registered Cosmetic Ingredient

1,5-Dihydroxynaphthalene

Also known as: Naphthalene-1,5-diol, 4-06-00-06554, BRN 2044951, 1,5-Dihydroxynapthalene, EINECS 201-487-4 (+1 more)

CAS 83-56-7

1,5-Dihydroxynaphthalene (CAS 83-56-7) is a chemical substance. Key regulatory status: REACH registered, 2 regulatory/inventory lists, cosmetic ingredient cross-reference; source data from EPA ToxValDB, EPA CPDat, AICIS, SCCS, ECHA REACH, ILO ICSC.

View cosmetic safety profile for 1,5-Naphthalenediol →

Cross-Vertical Regulatory Divergence

1,5-Dihydroxynaphthalene is prohibited in EU cosmetics at max 1.0% but has active industrial GHS classifications (H302, H317, H319, H411).

SOURCE Cross-vertical comparison Cosmetics: ingredients.eu_status/eu_max; Chemicals: ghs_classifications.signal_word/hazard_statement_code

SOURCE NOAEL studies

NOAEL studies

SOURCE Chemical inventory jurisdictions

Regulatory lists

SOURCE EU CLP Annex VI

GHS signal

Not classified

Chemical Identity

CAS, identifiers, formula, and alternate names for the matched substance record.

SOURCE DSSTox identifiers 11 fields

Name

1,5-Dihydroxynaphthalene

CAS Number

83-56-7

Molecular Formula

C10H8O2

InChI Key

BOKGTLAJQHTOKE-UHFFFAOYSA-N

Monoisotopic Mass

160.052429

Synonyms

Naphthalene-1,5-diol4-06-00-06554BRN 20449511,5-DihydroxynapthaleneEINECS 201-487-4UNII-P25HC23VH6

ICSC Chemical Safety

International Chemical Safety Card hazard and exposure summary.

SOURCE WHO/JECFA 1 records

Field	Value
Short-term Effects	The substance is mildly irritating to the eyes.
Routes of Exposure	The substance can be absorbed into the body by ingestion.

Functional Uses

Industrial and product-use categories associated with this substance.

SOURCE EPA CPDat 2 records

Dye

Regulatory Lists

Inventory, screening, and regulatory list matches from public chemical databases.

SOURCE EPA CPDat 2 records

List	Keyword	Source
Europe; Personal care - hair coloring	Danish Environmental Protection Agency	Danish EPA
Europe; Personal care; restricted	European Commission	CosIng

NOAEL Studies

Toxicology endpoints rendered from public NOAEL study rows.

SOURCE NOAEL studies Showing 18 of 18 studies

Value	Unit	Endpoint	Route	Species	Source
360	mg/kg bw/day	-	-	human	Regulatory source
P25HC23VH6	UNII	FDA UNII substance identifier	-	-	openFDA substances
50	mg/kg bw/day	LOAEL	oral	rat	COSMOS DB
=0.02	mg/kg bw/d	NOAEL	oral	rat	SCCS Opinion
=50	mg/kg bw/day	NOAEL	oral	Rat	ECHA
=50	mg/kg/day	NOAEL	-	-	SCCS Opinion
=50	mg/kg bw/day	NOAEL	oral	rat	SCCS Opinion
=50	mg/kg bw/day	NOAEL	-	-	SCCS Opinion
=50	mg/kg bw/d	NOAEL	oral	rat	SCCS Opinion
=360	mg/kg bw/day	NOAEL	-	rat	SCCS Opinion
=360	mg/kg bw/day	NOAEL	-	human	SCCS Opinion
=0.02	mg/kg bw/d	dermal absorption	oral	rat	Regulatory source
=50	mg/kg bw/d	dermal absorption	oral	rat	Regulatory source
360	mg/kg bw/day	developmental toxicity	-	rat	Regulatory source
50	mg/kg/day	genotoxicity	-	-	Regulatory source
50	mg/kg bw/day	genotoxicity	-	-	Regulatory source
50	mg/kg bw/day	repeated dose toxicity	oral	rat	Regulatory source
360	mg/kg bw/day	repeated dose toxicity	oral	rat	Regulatory source

Showing 18 of 18 studies

REACH Registration

Registration status from the ECHA REACH registered substances database.

SOURCE ECHA 1 records

Status	Name	EC Number	Link
Registered	Naphthalene-1,5-diol	201-487-4	ECHA overview →

Australian Status (AICIS)

Australian industrial chemicals inventory status and applicable conditions.

SOURCE AICIS inventory 1 records

Inventory Status

listed

SCCS Opinions

EU Scientific Committee opinions tied to the matched substance.

SOURCE SCCS Opinion 5 opinions

Opinion	Date	Conclusion	Max Conc.	Concerns
SCCS/1412/10	21 September 2010	safe	1.0%	sensitisation potential not excluded
SCCP/1060/07	21 March 2007	safe	1.5%	sensitisation not excluded
SCCP/1058/07	21 March 2007	safe	1.0%	sensitisation not excluded
SCCP/1060/06	2007-03-21	The SCCP is of the opinion that the information submitted is insufficient to allow a final risk assessment to be carried out. Before any further consideration, an in vitro percutaneous absorption study should be performed following the relevant SCCNFP/SCCP opinions and in accordance with its Notes of Guidance.	-	Insufficient data (missing in vitro percutaneous absorption study). Skin sensitiser per LLNA. Clastogenic activity in vitro (V79 cells), but no mutagenic potential in vivo.
SCCS/1365/10	21 September 2010	The SCCP is of the opinion that 1,5-Naphthalenediol as an ingredient in oxidative and non-oxidative hair dye formulations at a maximum on-head concentration of 1% does not pose a risk to the health of the consumer, apart from its sensitising potential.	1%	Sensitising potential. No mutagenic potential in vivo; genotoxicity/mutagenicity studies in finished formulations should be undertaken per SCCNFP/SCCP opinions and Notes of Guidance.

Cosmetic Safety Profile

Same-CAS cosmetic ingredient record for cross-vertical context.

SOURCE CosIng / Ingredients DB

EU Status

prohibited

Max

1.0%

Pharmaceutical Data

Same-CAS pharmaceutical records from drug and bioactivity sources.

SOURCE ChEMBL / DailyMed CHEMBL204658

ChEMBL Phase

Not listed

Adverse Events

Bioactivity

View full pharmaceutical profile →

Frequently Asked Questions

What is the NOAEL for 1,5-Dihydroxynaphthalene?

1,5-Dihydroxynaphthalene has 18 NOAEL studies in the database. The lowest reported value is 360 mg/kg bw/day in human. Source: Regulatory source.

What regulatory lists include 1,5-Dihydroxynaphthalene?

1,5-Dihydroxynaphthalene appears on 2 regulatory/inventory lists including Europe; Personal care - hair coloring, Europe; Personal care; restricted. Source: EPA CPDat.

Is 1,5-Dihydroxynaphthalene used in cosmetics?

Yes, 1,5-Dihydroxynaphthalene is also indexed as a cosmetic ingredient under the name 1,5-Naphthalenediol. View the full cosmetic safety profile on the ingredient page for detailed safety data, SCCS opinions, and regulatory status.

Where does the safety data for 1,5-Dihydroxynaphthalene come from?

Safety data is sourced from EPA ToxValDB, EPA CPDat, AICIS (Australian Industrial Chemicals Introduction Scheme), EPA DSSTox, ECHA REACH, ILO/WHO ICSC, CosIng / Ingredients DB, ChEMBL / DailyMed. All data traces to primary regulatory sources and is updated from official government databases.

Does 1,5-Dihydroxynaphthalene have different safety status in cosmetics vs industrial chemicals?

1,5-Dihydroxynaphthalene is prohibited in EU cosmetics at max 1.0% but has active industrial GHS classifications (H302, H317, H319, H411).

Is 1,5-Dihydroxynaphthalene used outside industrial chemicals?

1,5-Dihydroxynaphthalene also appears in cosmetics, pharmaceutical databases.