Moderate Colorant NOAEL Data GHS Classified Sensitization Data

Resorcinol Cosmetic

INCI: RESORCINOL

CAS Number
108-46-3
Function
oxidative hair dye coupler; color developer
Safety Rating
MODERATE

Regulatory Status

🇪🇺 EU Status restricted
EU Max Conc. 1.25% in oxidative hair dye formulations
🇺🇸 US Status permitted
US Notes CIR Expert Panel assessed resorcinol as safe in cosmetics (1986, reaffirmed 2006); OTC drug status for some applications; coal-tar dye exemption applies in hair dye context; thyroid disruption risk at high chronic doses not considered relevant at typical cosmetic exposure levels.

For full compliance data across 55 jurisdictions, use the Substance Compliance tool.

Safety Data

Margin of Safety (MoS)
adequate
Dermal Absorption
low
Sensitization
moderate

Calculate MoS for your specific formulation with the MoS Calculator.

Toxicological Studies

10 study endpoints found for Resorcinol Cosmetic. 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 400 mg/kg bw/day oral rat Chronic COSMOS_DB
NOAEL 260.7 mg/kg bw/day oral rat Short Term Toxicity COSMOS_DB
NOAEL 500 mg/kg bw/day oral rat Developmental COSMOS_DB
NOAEL 400 mg/kg bw/day oral rat Chronic COSMOS_DB
NOAEL 55 mg/kg bw/day oral rat Short Term Toxicity COSMOS_DB
NOAEL 150 mg/kg bw/day oral mouse Short Term Toxicity COSMOS_DB
NOAEL 520 mg/kg bw/day oral rat Subchronic COSMOS_DB
NOAEL 420 mg/kg bw/day oral mouse Subchronic COSMOS_DB
NOAEL 100 mg/kg bw/day oral rat Carcinogenicity COSMOS_DB
NOAEL 112 mg/kg bw/day oral mouse Carcinogenicity COSMOS_DB

GHS Hazard Classification

Globally Harmonized System classification per ECHA C&L inventory and ILO/WHO International Chemical Safety Cards.

Short-term Exposure Effects
The substance is irritating to the eyes, skin and respiratory tract. The substance may cause effects on the blood. This may result in the formation of methaemoglobin. The effects may be delayed. Medical observation is indicated.
Long-term Exposure Effects
Repeated or prolonged contact may cause skin sensitization in rare cases.
Routes of Exposure
The substance can be absorbed into the body by inhalation of its aerosol, through the skin and by ingestion.

SCCS NOAEL Values

NOAEL/LOAEL values cited in official SCCS opinions for Resorcinol Cosmetic.

NOAEL LOAEL Route Species Study DA% (SCCS) Opinion
80 mg/kg/day 250 mg/kg/day Oral Rat (Sprague-Dawley) Subchronic (90-day) (13 weeks (daily gavage)) 100 SCCS/1619/20 (2021)
27.5 mg/kg/day 55 mg/kg/day Oral Rat (F344/N) Short-term repeated dose (17-day) (17 days, 5 d/week gavage) 100 SCCS/1619/20 (2021)
101 mg/kg/day 304 mg/kg/day Oral Rat (Crl:CD(SD)) Reproductive toxicity (2-generation) (Drinking water; F0 ~133 days + F1/F2 to PND21) 100 SCCS/1619/20 (2021)

Sensitization Profile

Contact sensitization data for Resorcinol Cosmetic based on clinical patch test studies and IFRA standards.

Sensitization Rate
low
Allergen Class
dye
EU Allergen Listed
no
Patch Test Positive Rate
0.5%
Cross-reactivity Group
para-amino-group
Reaction Type
contact-dermatitis

Source: IVDK; NACDG; ESSCA

Expert Verdict

Resorcinol is a widely used meta-substituted coupler in oxidative hair dye, determining red-brown shade components. Its primary safety concern is endocrine disruption through thyroperoxidase inhibition affecting thyroid hormone synthesis. Rodent studies showed goitrogenic effects at doses exceeding 520 mg/kg/day; severe clinical hypothyroidism has been reported after prolonged high-concentration topical exposure. However, real-world risk assessment (MoS = 4000) concluded that typical hair dye exposure does not cause thyroid dysfunction. EU Annex III restricts to 1.25% in oxidative hair dye, with EAEU tightening post-mix concentration limits effective October 28, 2026.

⚠️
Concern Level: Moderate

Regulatory Flags

oxidative-dye hair-dye-coupler endocrine-disruptor tpo-inhibitor restricted eaeu-2026-update contact-sensitizer thyroid-concern ifra_fragrance fda_food_additive eu_cosing_listed

Frequently Asked Questions

Is Resorcinol Cosmetic safe in cosmetics?

Resorcinol is a widely used meta-substituted coupler in oxidative hair dye, determining red-brown shade components. Its primary safety concern is endocrine disruption through thyroperoxidase inhibition affecting thyroid hormone synthesis. Rodent studies showed goitrogenic effects at doses exceeding 520 mg/kg/day; severe clinical hypothyroidism has been reported after prolonged high-concentration topical exposure. However, real-world risk assessment (MoS = 4000) concluded that typical hair dye exposure does not cause thyroid dysfunction. EU Annex III restricts to 1.25% in oxidative hair dye, with EAEU tightening post-mix concentration limits effective October 28, 2026. The EU classifies Resorcinol Cosmetic as "restricted". Safety rating: MODERATE. 10 toxicological study endpoint(s) are available in our database.

Is Resorcinol Cosmetic allowed in the EU?

Resorcinol Cosmetic EU regulatory status: restricted. Maximum allowed concentration: 1.25% in oxidative hair dye formulations. This is based on EU Regulation 1223/2009 and its amendments.

What does Resorcinol Cosmetic do in cosmetics?

Resorcinol Cosmetic functions as: oxidative hair dye coupler; color developer. It is classified as a Colorant in our database. CAS number: 108-46-3.

What is the Margin of Safety for Resorcinol Cosmetic?

adequate The Margin of Safety (MoS) is calculated using SCCS methodology. A MoS above 100 is generally considered safe. Use the MoS Calculator tool to calculate MoS for your specific formulation and product category.

What is the NOAEL for Resorcinol Cosmetic?

The NOAEL (No Observed Adverse Effect Level) for Resorcinol Cosmetic is 400 mg/kg bw/day based on a Chronic study via oral route in rat. A total of 10 study endpoints are available. Source: COSMOS_DB.

Compliance Tools

Check Resorcinol Cosmetic 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 55 jurisdictions
 🧮
MoS Calculator
Calculate Margin of Safety using SCCS methodology
 ⚗️
Heavy Metal Limits
Compare limits across jurisdictions

Related Ingredients

Bismuth Oxychloride
Good
Yellow 5 Lake (CI 19140)
Good
CI 42090 (Brilliant Blue FCF)
Good
Eosin Y (D&C Red No. 22)
Moderate
Blue Tansy Oil (Tanacetum Annuum)
Moderate
Browse all 30,000+ ingredients →
📱

Is Resorcinol Cosmetic in Your Products?

Scan any product label with Piro — our free ingredient scanner. Point your camera at the ingredients list and get instant safety scores for every ingredient.

Try Piro Free →

Analyze Your Full Ingredient List

Paste any INCI list into the Decoder for instant safety analysis, or calculate the Margin of Safety for Resorcinol Cosmetic in your formulation.

Ingredient Decoder MoS Calculator