Poor Cosmetic Ingredient NOAEL Data GHS Classified

2-Naphthol (β-Naphthol) 🔴

INCI: 2-NAPHTHOL

CAS Number
135-19-3
Function
Historically used as hair dye coupler and antiseptic
Safety Rating
POOR

Regulatory Status

🇪🇺 EU Status prohibited
🇺🇸 US Status permitted
US Notes Not FDA-approved as a color additive; subject to stringent regulatory scrutiny. The related 1-Naphthol is CIR-reviewed as safe up to 3% in hair coloring, but 2-Naphthol has a worse toxicological profile

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

Safety Data

Margin of Safety (MoS)
not established
Dermal Absorption
high
Sensitization
high

Calculate MoS for your specific formulation with the MoS Calculator.

Toxicological Studies

4 study endpoints found for 2-Naphthol (β-Naphthol) 🔴. 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 150 mg/kg bw/day oral rat oral REACH
LOAEL 10080 other oral rat oral REACH
LOAEL 107 other oral rat oral REACH
LOAEL 298 other oral rabbit oral REACH

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 severely irritating to the eyes.
Long-term Exposure Effects
Repeated or prolonged contact may cause skin sensitization. The substance may have effects on the kidneys, blood and eyes. This may result in kidney impairment, anaemia and lens opacities.
Routes of Exposure
The substance can be absorbed into the body by inhalation of its aerosol, through the skin and by ingestion.

Expert Verdict

EU Annex II prohibited substance with mutagenicity concerns, skin and eye irritation, aquatic toxicity, and risk of methemoglobinemia. Do not formulate for EU-compliant markets.

⚠️
Concern Level: High

Regulatory Flags

eu_banned_cosmetics eu_cosing_listed

Frequently Asked Questions

Is 2-Naphthol (β-Naphthol) 🔴 safe in cosmetics?

EU Annex II prohibited substance with mutagenicity concerns, skin and eye irritation, aquatic toxicity, and risk of methemoglobinemia. Do not formulate for EU-compliant markets. The EU classifies 2-Naphthol (β-Naphthol) 🔴 as "prohibited". Safety rating: POOR. 4 toxicological study endpoint(s) are available in our database.

Is 2-Naphthol (β-Naphthol) 🔴 allowed in the EU?

2-Naphthol (β-Naphthol) 🔴 EU regulatory status: prohibited. This is based on EU Regulation 1223/2009 and its amendments.

What does 2-Naphthol (β-Naphthol) 🔴 do in cosmetics?

2-Naphthol (β-Naphthol) 🔴 functions as: Historically used as hair dye coupler and antiseptic. It is classified as a cosmetic ingredient in our database. CAS number: 135-19-3.

What is the Margin of Safety for 2-Naphthol (β-Naphthol) 🔴?

not established 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 2-Naphthol (β-Naphthol) 🔴?

The NOAEL (No Observed Adverse Effect Level) for 2-Naphthol (β-Naphthol) 🔴 is 150 mg/kg bw/day based on a oral study via oral route in rat. A total of 4 study endpoints are available. Source: REACH.

Compliance Tools

Check 2-Naphthol (β-Naphthol) 🔴 compliance across multiple jurisdictions:

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Ingredient Decoder
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82 Allergen Checker
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Substance Compliance
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MoS Calculator
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Heavy Metal Limits
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