Is Lawsone safe in cosmetics?
Lawsone has a safety rating of "MODERATE" in our database. EU status: prohibited. US status: permitted. 10 toxicological study endpoint(s) are available in our database.
Lawsone
Also known as: 4-08-00-02360, BRN 1565260, EINECS 201-496-3, UNII-TLH4A6LV1W, Henna
INCI: LAWSONE (2-HYDROXY-1,4-NAPHTHOQUINONE)
Lawsone (CAS 83-72-7) is a cosmetic cosmetic ingredient functioning as Hair dyeing (non-oxidizing hair colorant); historically proposed at up to 1.5%. NOAEL 1.3 mg/kg bw/day (PDF-verified against ToxValDB ECHA IUCLID); EU Regulation 1223/2009 status: prohibited. Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in pharmaceutical data.
View industrial chemical safety profile for CAS 83-72-7 →
Auto-generated CPSR Part A draft with source citations
Function
Hair dyeing (non-oxidizing hair colorant); historically proposed at up to 1.5% in finished products
Safety Rating
MODERATE
Chemistry & Identifiers
IUPAC Name
4-hydroxynaphthalene-1,2-dione
InChIKey
WVCHIGAIXREVNS-UHFFFAOYSA-N
Regulatory Status
EU EU Status
prohibited
US US Status
permitted
US Notes
Not specifically prohibited by FDA; however, coal tar hair dye exemption does not apply. Use requires safety substantiation under FD&C Act.
For full compliance data across multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Lawsone.
Calculate MoS for your specific formulation with the MoS Calculator.
Toxicological Studies
10 study endpoints found for Lawsone. 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 | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP_vision_codex |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP_vision_codex |
| NOAEL | =2 mg/kg bw/day | oral | - | NOAEL study | SCCNFP_vision_codex |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP_vision_codex |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP_vision_codex |
| NOAEL | =2 mg/kg bw/day | oral | - | NOAEL study | SCCNFP_vision_codex |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP_vision_codex |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP_vision_codex |
| NOAEL | =2 mg/kg bw/day | oral | - | NOAEL study | SCCNFP_vision_codex |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP_vision_codex |
Pre-Calculated Safety Assessment
Pre-calculated NOAEL → SED → MoS audit trail for Lawsone across SCCS product categories, with measured dermal absorption where available.
Expanded Dermal Absorption Data
Cross-database dermal penetration: EPA Dryad physics-based, Roberts Mendeley permeation, and SCCS-aggregated measured values.
Aggregated DA Values (1 records across 5 sources)
| Type | DA % | Method | Skin Model | SCCS Ref |
|---|---|---|---|---|
| measured_sccs_opinion | 4.08% | - | - | SCCS/1511/13 |
Additional Ingredient Properties
1 property record from structured ingredient metadata.
hair_dye
{"cas_number": "83-72-7", "ingredient_class": "henna", "color_index_CI_number": "75480", "chemical_class": "lawsone", "molecular_weight_Da": "174.15", "color_result_on_hair": "Red-orange", "shade_range": "red", "primary_function": "direct_deposit", "requires_developer": "no", "lift_capability_levels": "0", "deposit_only": "yes", "permanence": "permanent", "wash_fastness_shampoos": "30+", "light_fa…
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Dye
Expert Verdict
Expert safety assessment and concern-level summary for Lawsone.
Regulatory Flags
colorant
NOAEL Studies Summary
View details ->Public NOAEL study rows linked to Lawsone by CAS number or substance name.
Studies
40
Lowest NOAEL
2
Highest NOAEL
300
Units vary across source rows: mg/kg bw/day, mg/kg
SCCNFP_vision_codex
Dermal Absorption
View details ->| Absorption % | Method | Vehicle |
|---|---|---|
| 4.08% | SCCS opinion extraction | - |
Known Synonyms
4-08-00-02360
BRN 1565260
EINECS 201-496-3
UNII-TLH4A6LV1W
Henna
Chemical Function
Dye
Regulatory Lists
Europe; Personal care - hair coloring
Europe; Personal care - hair coloring
Europe; Personal care - hair coloring
Europe; Personal care - hair coloring
Canada; pharmaceutical
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
LAWSONE
ChEMBL ID
CHEMBL240963
Frequently Asked Questions
Is Lawsone allowed in the EU?
Lawsone EU regulatory status: prohibited. This is based on EU Regulation 1223/2009 and its amendments.
What does Lawsone do in cosmetics?
Lawsone functions as: Hair dyeing (non-oxidizing hair colorant); historically proposed at up to 1.5% in finished products. It is classified as a cosmetic ingredient in our database. CAS number: 83-72-7.
What is the NOAEL for Lawsone?
The NOAEL (No Observed Adverse Effect Level) for Lawsone is =2 mg/kg bw/day based on a irritation study via oral route in rabbit. A total of 10 study endpoints are available. Source: SCCNFP_vision_codex.
Is Lawsone used outside cosmetics?
Lawsone also appears in pharmaceutical data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Compliance Tools
Check Lawsone compliance across multiple jurisdictions:
Ingredient Decoder
Paste a full ingredient list for instant analysis
82 Allergen Checker
Check for EU declarable fragrance allergens
Substance Compliance
Check compliance across multiple jurisdictions
MoS Calculator
Calculate Margin of Safety using SCCS methodology
Heavy Metal Limits
Compare limits across jurisdictions
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