Poor Cosmetic Ingredient NOAEL Data GHS Classified Sensitization Data

Formaldehyde

INCI: FORMALDEHYDE

CAS Number

50-00-0

Function

Nail Hardener, Preservative, Keratin Cross-Linker

Safety Rating

POOR

Regulatory Status

🇪🇺 EU Status prohibited

EU Max Conc. 2.2%

🇺🇸 US Status permitted

US Notes IARC Group 1 carcinogen. CIR 1984 (reaffirmed 2006): safe as preservative at minimal effective concentration not exceeding recommended limits. FDA caution-only stance diverges significantly from EU approach.

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

10 study endpoints found for Formaldehyde. 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 bw/day	oral	dog	Subchronic	COSMOS_DB
NOAEL	150 mg/kg bw/day	oral	rat	Subchronic	COSMOS_DB
NOAEL	185 mg/kg bw/day	oral	mouse	Developmental	COSMOS_DB
NOAEL	9.4 mg/kg bw/day	oral	dog	Developmental	COSMOS_DB
NOAEL	540 mg/kg bw/day	oral	mouse	Reproductive	COSMOS_DB
NOAEL	100 mg/kg bw/day	oral	rat	Subchronic	COSMOS_DB
NOAEL	100 mg/kg bw/day	oral	dog	Subchronic	COSMOS_DB
NOAEL	125 mg/kg bw/day	oral	rat	Short Term Toxicity	COSMOS_DB
NOAEL	95 mg/kg bw/day	oral	rat	Carcinogenicity	COSMOS_DB
NOAEL	300 mg/kg bw/day	oral	rat	Carcinogenicity	COSMOS_DB

GHS Hazard Classification

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

Signal Word

DANGER

Pictograms

flam;flame; skull;toxic; cancer;health haz

Hazard Statements

Extremely flammable gas Fatal if inhaled Causes serious eye irritation May cause cancer if inhaled May cause an allergic skin reaction May cause respiratory irritation

Short-term Exposure Effects

The substance is severely irritating to the eyes and respiratory tract. Inhalation of high concentrations may cause lung oedema, but only after initial corrosive effects on the eyes and the upper respiratory tract have become manifest.

Long-term Exposure Effects

Repeated or chronic inhalation of the vapour may cause chronic inflammation of the upper respiratory tract. Repeated or prolonged contact may cause skin sensitization. This substance is carcinogenic to humans.

Routes of Exposure

The substance can be absorbed into the body by inhalation.

Sensitization Profile

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

Sensitization Rate

high

Allergen Class

preservative

EU Allergen Listed

Patch Test Positive Rate

2.5%

Cross-reactivity Group

formaldehyde-releaser-group

Reaction Type

contact-dermatitis

IFRA Restricted

Source: ESSCA 2019/20; IVDK; FDA

Expert Verdict

IARC Group 1 carcinogen. EU effectively banned in cosmetics 2022. Even at low concentrations (0.006%), can trigger allergic contact dermatitis in sensitized individuals. FDA has not acted to restrict it in the US. No acceptable cosmetic use case in modern formulation. Avoid entirely — use alternative nail strengtheners (hydroxypropyl chitosan, hydrolyzed keratin, ATBC-plasticized systems).

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Concern Level: High

Regulatory Flags

iarc_group_1_carcinogen eu_banned_2022 reproductive_toxin occupational_hazard sensitizer_at_0006pct nail_hardener_risk formaldehyde_releaser_concern avoid endocrine_disruptor prop65 eu_banned_cosmetics fda_food_additive eu_cosing_listed

Frequently Asked Questions

Is Formaldehyde safe in cosmetics?

Is Formaldehyde allowed in the EU?

Formaldehyde EU regulatory status: prohibited. Maximum allowed concentration: 2.2%. This is based on EU Regulation 1223/2009 and its amendments.

What does Formaldehyde do in cosmetics?

Formaldehyde functions as: Nail Hardener, Preservative, Keratin Cross-Linker. It is classified as a cosmetic ingredient in our database. CAS number: 50-00-0.

What is the Margin of Safety for Formaldehyde?

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 Formaldehyde?

The NOAEL (No Observed Adverse Effect Level) for Formaldehyde is 100 mg/kg bw/day based on a Subchronic study via oral route in dog. A total of 10 study endpoints are available. Source: COSMOS_DB.

Is Formaldehyde classified as hazardous under GHS?

Formaldehyde carries a GHS signal word of "DANGER". Hazard statements: Extremely flammable gas Fatal if inhaled Causes serious eye irritation May cause cancer if inhaled May cause an allergic skin reaction May cause respiratory irritation. This classification is based on the ILO/WHO International Chemical Safety Card and ECHA C&L inventory data. Note: GHS classification applies to the pure substance — at cosmetic use concentrations, hazard thresholds may not be met.

Compliance Tools

Check Formaldehyde compliance across multiple jurisdictions:

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Ingredient Decoder

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82 Allergen Checker

Check for EU declarable fragrance allergens

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Substance Compliance

Check compliance across 55 jurisdictions

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MoS Calculator

Calculate Margin of Safety using SCCS methodology

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Heavy Metal Limits

Compare limits across jurisdictions

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