Moderate Active Ingredient NOAEL Data SCCS/CIR Reviewed Dermal Penetration

Kojic Acid

Also known as: 5-18-02-00516, BRN 0120895, EINECS 207-922-4, 5-Hydroxy-2-(hydroxymethyl)-4-pyrone, UNII-6K23F1TT52 (+2 more)

INCI: KOJIC ACID

Kojic Acid (CAS 501-30-4) is a cosmetic active ingredient functioning as Tyrosinase inhibitor; chelates copper at the enzyme's active site blocking both. NOAEL 2 mg/kg bw/day (PDF-verified against ToxValDB ECHA IUCLID); EU Regulation 1223/2009 status: restricted, max 1%; 5 safety opinions reviewed (sccs). 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 501-30-4 →

Auto-generated CPSR Part A draft with source citations

CAS Number

501-30-4

View industrial chemical safety profile →

Function

Tyrosinase inhibitor; chelates copper at the enzyme's active site blocking both monophenolase and diphenolase activity; clinically used at 1–2.5% for melasma and senile pigmentation

Safety Rating

MODERATE

Chemistry & Identifiers

ChEBI: CHEBI:43572 UNII: 6K23F1TT52 Wikidata: Q416285

Regulatory Status

EU EU Status restricted

EU Max Conc. 1%

US US Status permitted

US Notes No specific FDA concentration restriction for cosmetic brightening use. Typically used at 1–2.5% in OTC brightening products. Not classified as a drug at cosmetic concentrations. Not GRAS-listed for OTC skin bleaching.

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

Safety Data

Margin of Safety, dermal absorption, and sensitization profile summaries for Kojic Acid.

Calculate MoS for your specific formulation with the MoS Calculator.

Toxicological Studies

10 study endpoints found for Kojic Acid. 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	=100 mg/kg	oral	rat	repeated dose toxicity	CIR_vision_codex
NOAEL	=100 mg/kg	oral	rat	repeated dose toxicity	CIR_vision_codex
NOAEL	=100 mg/kg	oral	rat	repeated dose toxicity	CIR_vision_codex
NOAEL	=100 mg/kg	oral	rat	repeated dose toxicity	CIR_vision_codex
NOAEL	=125 mg/kg	dermal	rat	NOAEL study	CIR_vision_codex
NOAEL	=125 mg/kg	dermal	rat	NOAEL study	CIR_vision_codex
NOAEL	=125 mg/kg	dermal	rat	NOAEL study	CIR_vision_codex
NOAEL	=125 mg/kg	dermal	rat	NOAEL study	CIR_vision_codex
NOAEL	=150 mg/kg	oral	mouse	repeated dose toxicity	CIR_vision_codex
NOAEL	=150 mg/kg	oral	mouse	repeated dose toxicity	CIR_vision_codex

Safety Opinions

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

sccs SCCS/1637/21 16 March 2022

Verdict: safe

NOAEL: 23.8 mg/kg bw/day (not specified)

Max Concentration: 1% in general

al endocrine disrupting properties of Kojic acid, the SCCS is of the opinion that Kojic acid is safe when used as a skin lightening agent in cosmetic products at concentrations of up to 1%. 2. Alternatively, what is according to the SCCS the maximum concentration considered safe for use of Ko

sccs SCCS/1637/21 16 March 2022

Verdict: safe

NOAEL: 23.8 mg/kg bw/day (not specified)

Max Concentration: 1% in leave-on

al endocrine disrupting properties of Kojic acid, the SCCS is of the opinion that Kojic acid is safe when used as a skin lightening agent in cosmetic products at concentrations of up to 1%. 2. Alternatively, what is according to the SCCS the maximum concentration considered safe for use of Ko

sccs SCCS/1637/21 16 March 2022

Verdict: safe

NOAEL: 5.85 mg/kg bw/day (not specified)

Max Concentration: 1% in general

al endocrine disrupting properties of Kojic acid, the SCCS is of the opinion that Kojic acid is safe when used as a skin lightening agent in cosmetic products at concentrations of up to 1%. 2. Alternatively, what is according to the SCCS the maximum concentration considered safe for use of Ko

sccs SCCS/1637/21 16 March 2022

Verdict: safe

NOAEL: 5.85 mg/kg bw/day (not specified)

Max Concentration: 1% in leave-on

al endocrine disrupting properties of Kojic acid, the SCCS is of the opinion that Kojic acid is safe when used as a skin lightening agent in cosmetic products at concentrations of up to 1%. 2. Alternatively, what is according to the SCCS the maximum concentration considered safe for use of Ko

sccs SCCS/1637/21 16 March 2022

Verdict: safe

NOAEL: 6 mg/kg bw/day (oral)

Max Concentration: 1% in general

al endocrine disrupting properties of Kojic acid, the SCCS is of the opinion that Kojic acid is safe when used as a skin lightening agent in cosmetic products at concentrations of up to 1%. 2. Alternatively, what is according to the SCCS the maximum concentration considered safe for use of Ko

Pre-Calculated Safety Assessment

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

SCCS NOAEL Values

NOAEL/LOAEL values cited in official SCCS opinions for Kojic Acid.

NOAEL	LOAEL	Route	Species	Study	DA% (SCCS)	Opinion
6 mg/kg/day	23.8 mg/kg/day	Oral	Rat (male)	Repeated dose (28-day) (28 days (dietary))	100	SCCS/1637/21 (2022)
15.5 mg/kg/day	-	Oral	Rat (male)	Subacute/repeated dose (20-week feeding) (20 weeks (dietary))	100	SCCS/1637/21 (2022)
100 mg/kg/day	-	Dermal	Rat (Wistar)	Repeated dose (28-day) (28 days)	N/A	SCCS/1098/14 (2014)
-	-	Oral	Rat/Mouse	Developmental toxicity (Gestational period)	100	SCCS/1098/14 (2014)

Dermal Penetration Profile

Skin absorption and penetration characteristics of Kojic Acid, relevant to systemic exposure and MoS calculations.

Absorption %

10-18%

Penetration Level

epidermis

Penetration Depth

epidermis

Molecular Weight

142.1 Da

Log P

-0.75

Systemic Absorption

minimal

Topical Bioavailability

6-14%

Safety Margin Factor

moderate

Vehicle Dependent

Yes — absorption varies by formulation

Source: J Cosmet Dermatol 2011

IARC Carcinogenicity

International Agency for Research on Cancer (WHO) monograph evaluation.

IARC Group

3

Volume

79

Evaluation Year

2000

Endocrine Disruptor Evidence (Expanded)

Cross-referenced EDC classifications, mechanism data, and dose-response evidence from EDLists, SIN List, and cosmetic-specific detail sources.

Under investigation Evidence: Limited (2022)

Health effects: Yes

Affected pathways: Thyroid

Regulatory framework: Cosmetics

Source list: II (former)

Cosmetic-Specific Mechanism

Category: other

Receptor targets: TR, ERα

LOEC: 1 µM (TPO inhibition)

EU status: restricted (max 1%); SCCS 2024 safe at ≤1%; ED review 2019

inhibitor (thyroid peroxidase); weak agonist (ER)

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.

JPKR Japan/Korea Cosmetics

Korea (Restricted): max 1.0

Additional Jurisdictional Restrictions (5)

Jurisdiction	Status	Max %	Product Type
CN	banned	-	-
AU	restricted	1.0	skin lightening
GCC	banned	-	Non-compliant skin lightening products
BR	banned	-	-
UK	restricted	-	-

Expanded Dermal Absorption Data

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

Aggregated DA Values (2 records across 5 sources)

Type	DA %	Method	Skin Model	SCCS Ref
measured	1.0	method=measured; type=in_vitro	-	-
measured_sccs_opinion	31.0%	-	-	SCCS/1637/21

Typical Use Concentrations

Reported concentration ranges per product category from SCCS/CIR/industry sources.

Product Category	Typical Range	Max Reported	Source
Serum	0.5–2	2	CIR/SCCS

Additional Ingredient Properties

10 property records from structured ingredient metadata.

acne

{"cas_number": "501-30-4", "anti_acne_mechanism": "antibacterial/anti_inflammatory", "comedogenicity_rating_0_to_5": "2", "acne_type_efficacy": "inflammatory", "p_acnes_mic_ug_per_ml": ">500", "sebum_reduction_pct_clinical": "5-10", "prescription_required_usa": "No", "otc_drug_monograph_category": "No", "max_otc_concentration_pct": "4", "rx_only_concentration_pct": "6-20", "japan_quasi_drug_anti_a…

anti_aging

{"anti_aging_claim": "brightening, dark-spot-reduction, antioxidant-protection", "mechanism_of_action": "Copper chelator, tyrosinase inhibitor, prevents melanin formation", "target_skin_layer": "epidermis", "collagen_stimulation": "No", "elastin_protection": "No", "wrinkle_reduction_pct": "0-5", "clinical_study_duration_weeks": "12", "sample_size": "40", "double_blind": "Yes", "placebo_controlled"…

anti_pollution

{"cas_number": "501-30-4", "ingredient_class": "antioxidant_pollution_shield", "primary_mechanism": "free_radical_scavenging", "pollution_types_targeted": "PM2_5", "IR_A_protection": "no", "visible_light_protection": "no", "digital_screen_protection_claim": "no", "PAH_neutralization": "no", "ozone_protection": "no", "mitochondrial_protection": "no", "Nrf2_activation": "no", "AhR_pathway_modulation…

comedogenicity_detail

{"comedogenicity_rating": "0", "irritancy_rating": "2", "skin_type_suitability": "oily,combination,normal,mature", "acne_safe": "caution", "source": "Skin brightener"}

concentration

{"min_concentration_pct": "1.0", "max_concentration_pct": "3.0", "typical_concentration_pct": "2.0", "product_type": "Moisturizer", "function_at_concentration": "Brightening", "source": "Clinical literature"}

cost_pricing

{"cost_tier": "mid-range", "estimated_cost_per_kg_usd_low": "45", "estimated_cost_per_kg_usd_high": "85", "natural_premium_markup_pct": "0", "organic_certified_premium_pct": "0", "supply_chain_volatility": "medium", "primary_source_region": "Japan/China", "bulk_discount_threshold_kg": "25", "seasonal_price_variation": "medium", "commodity_or_specialty": "specialty", "substitute_ingredients": "Alph…

depigmentation

{"cas_number": "501-30-4", "ingredient_class": "tyrosinase_inhibitor", "primary_mechanism_of_action": "Copper chelation at tyrosinase active site preventing enzymatic activity", "secondary_mechanisms": "ROS scavenging, melanin polymerization inhibition", "molecular_target": "tyrosinase", "tyrosinase_inhibition_IC50_uM": "1.6-2.8", "tyrosinase_inhibition_type": "copper_chelation", "melanin_reductio…

dermal_absorption

{"molecular_weight_da": "142.1", "log_p_value": "-0.75", "skin_penetration_level": "epidermis", "penetration_depth": "epidermis", "absorption_pct": "10-18", "systemic_absorption": "minimal", "penetration_enhancer": "no", "occlusion_effect": "no", "vehicle_dependent": "yes", "skin_barrier_effect": "neutral", "bioavailability_topical_pct": "6-14", "safety_margin_factor": "moderate", "source": "J Cos…

Function Categories & List Membership

Cosmetic/Chemical Function Categories

Antioxidant

Expert Verdict

Expert safety assessment and concern-level summary for Kojic Acid.

Regulatory Flags

tyrosinase-inhibitor brightening eu-restricted eu-regulation-2024-996 annex-iii-1pct-face-hand sensitization-risk-1-2pct oxidation-instability copper-chelator melasma hyperpigmentation quasi-drug-japan-1988 japan-suspended-2003-reinstated-2005 aak-combination-evidence endocrine_disruptor

NOAEL Studies Summary

View details ->

Public NOAEL study rows linked to Kojic Acid by CAS number or substance name.

Studies

100

Lowest NOAEL

0.069

Highest NOAEL

2600

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

CIR_vision_codex SCCS_vision_codex

Dermal Absorption

View details ->

Absorption %	Method	Vehicle
1.0	method=measured; type=in_vitro	-
31.0%	SCCS opinion extraction	-

Known Synonyms

5-18-02-00516 BRN 0120895 EINECS 207-922-4 5-Hydroxy-2-(hydroxymethyl)-4-pyrone UNII-6K23F1TT52 Kojisaeure acido kojico

Chemical Function

Antioxidant

Regulatory Lists

Canada; Personal care; Substances in PCP - Canada (4/2014) Canada; pharmaceutical

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

KOJIC ACID

ChEMBL ID

CHEMBL287556

View full pharmaceutical profile →

Frequently Asked Questions

Is Kojic Acid safe in cosmetics?

Kojic Acid 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 sccs.

Is Kojic Acid allowed in the EU?

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

What does Kojic Acid do in cosmetics?

Kojic Acid functions as: Tyrosinase inhibitor; chelates copper at the enzyme's active site blocking both monophenolase and diphenolase activity; clinically used at 1–2.5% for melasma and senile pigmentation. It is classified as a Active Ingredient in our database. CAS number: 501-30-4.

What is the NOAEL for Kojic Acid?

The NOAEL (No Observed Adverse Effect Level) for Kojic Acid is =100 mg/kg based on a repeated dose toxicity study via oral route in rat. A total of 10 study endpoints are available. Source: CIR_vision_codex.

Is Kojic Acid used outside cosmetics?

Kojic Acid also appears in pharmaceutical data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.

Compliance Tools

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