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 food safety data.
Function
Hair dyeing (non-oxidizing hair colorant); historically proposed at up to 1.5% in finished products
Editorial assessment
MODERATE
Preliminary editorial note — not a computed safety verdict.
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 Opinion |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP Opinion |
| NOAEL | =2 mg/kg bw/day | oral | - | NOAEL study | SCCNFP Opinion |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP Opinion |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP Opinion |
| NOAEL | =2 mg/kg bw/day | oral | - | NOAEL study | SCCNFP Opinion |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP Opinion |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP Opinion |
| NOAEL | =2 mg/kg bw/day | oral | - | NOAEL study | SCCNFP Opinion |
| NOAEL | =2 mg/kg bw/day | - | rabbit | irritation | SCCNFP Opinion |
Pre-Calculated Safety Assessment
Conditional — safe only within SCCS limits: only as constituent of assessed Henna/Lawsonia inermis hair dye, not standalone lawsone: assessed Henna batches 1271 and 830.72 with lawsone content max 1.4%, formulated/applied as indicated (e.g. 100 g Henna powder + 300 ml boiling water); other extracts/body-paint uses not covered; reassessment of lawsone genotoxicity desirable
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 |
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Dye
Editorial summary
Preliminary editorial summary for Lawsone — not a computed safety verdict. See the sourced toxicological data above.
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 Opinion
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 food safety data.
SOURCE
EFSA / FDA GRAS
food_additives
Food Safety Data
Same-CAS food additive or FDA GRAS records from the core public database.
Food Name
Henna extract (Lawsone)
Food Category
colorant
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 Opinion.
Is Lawsone used outside cosmetics?
Lawsone also appears in food safety 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
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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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