Is Formaldehyde safe in cosmetics?
Formaldehyde has a safety rating of "POOR" in our database. EU status: prohibited. US status: permitted. 10 toxicological study endpoint(s) are available in our database.
Formaldehyde
Also known as: Caswell No. 465, EINECS 200-001-8, EPA Pesticide Chemical Code 043001, Formaldehyde, gas, Formalin 40 (+15 more)
INCI: FORMALDEHYDE
Formaldehyde (CAS 50-00-0) is a cosmetic cosmetic ingredient functioning as Nail Hardener, Preservative, Keratin Cross-Linker. NOAEL 9.4 mg/kg bw/day (cross-referenced against ToxValDB ECHA IUCLID); EU Regulation 1223/2009 status: prohibited, max 2.2%; GHS signal word DANGER. Industrial safety data is also available in the chemical safety database. Same-CAS public records also appear in industrial chemical safety, pharmaceutical, and food safety data.
View industrial chemical safety profile for CAS 50-00-0 →
Auto-generated CPSR Part A draft with source citations
Cross-Vertical Regulatory Divergence
Formaldehyde is prohibited in EU cosmetics at max 2.2% but has active industrial GHS classifications (H301, H311, H314, H317, H318, H330, H331, H341).
Source: Cosmetics: ingredients.eu_status/eu_max; Chemicals: ghs_classifications.signal_word/hazard_statement_code
Function
Nail Hardener, Preservative, Keratin Cross-Linker
Safety Rating
POOR
Chemistry & Identifiers
IUPAC Name
formaldehyde
InChIKey
WSFSSNUMVMOOMR-UHFFFAOYSA-N
Regulatory Status
EU EU Status
prohibited
EU Max Conc.
2.2%
US 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 multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Formaldehyde.
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 | 20 mg/kg bw/day | oral | rat | Short Term Toxicity | COSMOS_DB |
| NOAEL | 21 mg/kg bw/day | oral | rat | Chronic | COSMOS_DB |
| NOAEL | 75 mg/kg bw/day | oral | rat | Carcinogenicity | COSMOS_DB |
| NOAEL | 95 mg/kg bw/day | oral | rat | Carcinogenicity | COSMOS_DB |
| NOAEL | =10 mg/kg bw/day | oral | rat | repeated dose toxicity | SCCS_vision_codex |
| NOAEL | =10 mg/kg bw/day | oral | rat | repeated dose toxicity | SCCS_vision_codex |
| NOAEL | =10 mg/kg bw/day | oral | rat | repeated dose toxicity | SCCS_vision_codex |
| NOAEL | =10 mg/kg bw/day | oral | rat | repeated dose toxicity | SCCS_vision_codex |
| NOAEL | =21 mg/kg bw/day | oral | rat | carcinogenicity | SCCS_vision_codex |
| NOAEL | =21 mg/kg bw/day | oral | rat | carcinogenicity | SCCS_vision_codex |
GHS Hazard Classification
Globally Harmonized System classification per ECHA C&L inventory and ILO/WHO International Chemical Safety Cards.
Signal Word
DANGER
Pictograms
FlamFlameSkullToxicCancerHealth 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.
Pre-Calculated Safety Assessment
Pre-calculated NOAEL → SED → MoS audit trail for Formaldehyde across SCCS product categories, with measured dermal absorption where available.
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
no
Patch Test Positive Rate
2.5%
Cross-reactivity Group
formaldehyde-releaser-group
Reaction Type
contact-dermatitis
IFRA Restricted
Source: ESSCA 2019/20; IVDK; FDA
EPA ToxValDB — Toxicity Values
10 toxicity values from EPA ToxValDB (aggregated from CCTE, HPV, ToxRefDB, IRIS, and other regulatory dossiers).
| Endpoint | Value | Species | Route | Duration | Source |
|---|---|---|---|---|---|
| LEL | >20 mg/L | Rat | inhalation | acute | EPA TSCA 8e |
| LEL | <21 mg/L | Rat | inhalation | acute | EPA TSCA 8e |
| LEL | =17 mg/L | Rat | inhalation | acute | EPA TSCA 8e |
| LEL | =1.28 ppm | Human | oral | - | EPA TSCA 8e |
| LOAEL | =0.5 mg/m3 | Human | inhalation | acute | TX TCEQ |
| NOAEL | =0.09 mg/m3 | Human | inhalation | chronic | TX TCEQ |
| cancer slope factor | =0.021 (mg/kg-day)-1 | Human | inhalation | chronic | Cal OEHHA |
| cancer slope factor | =0.021 (mg/kg-day)-1 | Human | oral | chronic | Cal OEHHA |
| RfD | =0.2 mg/kg-day | Human | oral | - | OW Drinking Water Standards |
| OEL | =0.368419 mg/m3 | Human | inhalation | - | EU SCOEL |
IARC Carcinogenicity
International Agency for Research on Cancer (WHO) monograph evaluation.
IARC Group
1
Volume
Sup 7, 62, 88, 100F
Evaluation Year
2009
EU CLP Annex VI Harmonized Classification
Legally binding harmonized classification per Regulation (EC) No 1272/2008 (CLP) Annex VI.
Signal Word
Danger
Pictograms
Health HazardAcute ToxicityCorrosive
Hazard Class and Category
Carc. 1B; Muta. 2; Acute Tox. 2; Acute Tox. 4; Skin Corr. 1B; Skin Sens. 1A
Hazard Statements
- H350 May cause cancer
- H341 Suspected of causing genetic defects
- H330 Fatal if inhaled
- H302 Harmful if swallowed
- H314 Causes severe skin burns and eye damage
- H317 May cause an allergic skin reaction
Specific Concentration Limits / M-factors
inhalation: ATE = 100.0 ppmV gases; oral: ATE = 500.0 mg/kg bw; STOT SE 3; H335: C ≥ 5.0%; Skin Corr. 1B; H314: C ≥ 25.0%; Skin Irrit. 2; H315: 5.0% ≤ C < 25.0%; Eye Irrit. 2; H319: 5.0% ≤ C < 25.0%
Inserted via ATP: ATP22
Sensitization AOP Dashboard
Adverse Outcome Pathway data across 5 assays (DPRA, KeratinoSens, hCLAT, LLNA, NESIL) aggregated from public sources.
DPRA Cys %
48.6%
DPRA Lys %
2.4%
KeratinoSens IC50
110 µM
hCLAT CV75
9.7 µg/mL
LLNA EC3
2.25%
NESIL
29 µg/cm²
LLNA: Moderate (1B)
GHS: 1B
Human: positive
Source: LLNA: Gerberick et al. (2005) | Ryan et al. (2002); DPRA: Bauch et al. 2012 [DOI:10.1016/j.yrtph.2012.05.013] | Gerberick et al. 2007 [DOI:10.1093/toxsci/kfm064]; KS: Emter et al. 2010 [DOI:10.1016/j.taap.2010.03.009] | Bauch et al. 2012 [DOI:10.1016/j.yrtph.2012.05.013]; hCLAT: Urbisch et al. 2015 [DOI:10.1016/j.yrtph.2014.12.008] | Bauch et al. 2012 [DOI:10.1016/j.yrtph.2012.05.013]; HPPT: [27] Kligman AM (1966): https://doi.org/10.1038/jid.1966.160
HRIPT Human Patch Test Studies
5 human repeat insult patch tests aggregated from dermatological literature.
| Test Type | N | Sensitized | Dose µg/cm² | NESIL µg/cm² | Potency |
|---|---|---|---|---|---|
| HRIPT | - | 0 | - | - | strong |
| HMT | - | 0 | 1148.28 | - | - |
| HRIPT | - | 0 | 28.68 | - | - |
| HRIPT | - | 0 | 286.75 | - | - |
| HRIPT | - | 0 | 860.25 | - | - |
Endocrine Disruptor Evidence (Expanded)
Cross-referenced EDC classifications, mechanism data, and dose-response evidence from EDLists, SIN List, and cosmetic-specific detail sources.
Cosmetic-Specific Mechanism
Category: preservative
Receptor targets: ERα (via reactive adducts on ER)
LOEC: 10 µM
EU status: banned (CMR 1B since 2009) except for nail hardeners (max 2.2%); banned in hair straightening 2024
covalent ER modifier (genotoxic)
Dose-Response Data Points
| Endpoint | Target | Value | Direction |
|---|---|---|---|
| ERα-mediated transcription; MCF-7 proliferation | ERα | EC50/IC50: EC50 not formally calculated; proliferative effect at 1–100 µM; LOEC: 1 µM; NOEC: not established mixed | weak agonist |
| AR transcriptional activity | AR | EC50/IC50: LOEC ~10 µM (anti-androgenic effects reported); LOEC: 10 µM; NOEC: not established mixed | antagonist (indirect via DNA adducts / protein crosslinking) |
| Aryl hydrocarbon receptor (AhR) activation | AhR | EC50/IC50: EC50 not precisely reported; active at ≥50 µM; LOEC: 50 µM; NOEC: not established mixed | weak inducer (via oxidative stress / NF-κB crosstalk) |
| hTPO enzyme activity inhibition | Thyroid peroxidase (TPO) | EC50/IC50: IC50 not precisely reported; active >20% at 50–100 µM; LOEC: ~50 µM (estimated); NOEC: not established mixed | inhibitor |
| Glucocorticoid receptor binding / transactivation | GR (glucocorticoid receptor) | EC50/IC50: LOEC ~10 µM (GR DNA binding disruption); LOEC: ~10 µM; NOEC: not established mixed | antagonist (indirect via protein crosslinking / Schiff base formation) |
| E2 and T production in H295R cells | Steroidogenesis (CYP17/CYP19) | EC50/IC50: LOEC ~1–5 µM (sub-cytotoxic window; E2 ↑ reported); LOEC: ~1 µM; NOEC: not established mixed | modulator (at low, sub-cytotoxic concentrations) |
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Full
Tonnage Band
1,000,000 - 10,000,000 tonnes
Substance Type
SUBSTANCE
SVHC Candidate
No
Hazard classification: Restricted (Annex XVII)
EU CosIng Annex Listing
European Commission CosIng database Annex references per Regulation (EC) No 1223/2009.
Annex II — Prohibited
Ref: 1577
(EU) 2019/831
CMR: Carcinogenic Cat. 1B(),Mutagenic Cat. 2()
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.
SA Saudi SFDA (II - Prohibited)
ASEAN Cosmetic Directive (II)
Ref: 1577
JPKR Japan/Korea Cosmetics
Japan (Prohibited): Must not be used (formalin)
Korea (Prohibited): Must not be used as formaldehyde source
Korea (Prohibited): ; Category: General
BRIN Brazil/India Cosmetics
India: Prohibited (GNRAS)
Additional Jurisdictional Restrictions (10)
| Jurisdiction | Status | Max % | Product Type |
|---|---|---|---|
| JP | banned | - | All cosmetics |
| CN | banned | - | - |
| IN | permitted_preservative | 0.2 | all cosmetics except oral hygiene |
| IN | permitted_preservative | 0.1 | oral hygiene products only |
| AU | restricted | 5.0 | nail hardeners |
| AU | restricted | 0.2 | general cosmetics |
| GCC | banned | - | All cosmetics |
| BR | banned | - | Only banned as aerosol hair straightening ingredient; other uses restricted per RDC 645/2022 |
Additional Ingredient Properties
6 property records from structured ingredient metadata.
allergen_detail
{"eu_allergen_listed": "no", "allergen_class": "preservative", "cross_reactivity_group": "formaldehyde-releaser-group", "patch_test_frequency_pct": "2.5", "sensitization_rate": "high", "common_reaction_type": "contact-dermatitis", "ifra_restricted": "yes", "source": "ESSCA 2019/20; IVDK; FDA"}
ecotoxicity
{"biodegradable": "yes", "biodegradation_days": "1-7", "bioaccumulative": "no", "aquatic_toxicity_level": "high", "coral_reef_safe": "no", "marine_toxicity": "toxic to aquatic life", "freshwater_toxicity": "high fish toxicity", "endocrine_disruptor": "no", "persistent_organic_pollutant": "no", "microplastic": "no", "nano_particle": "no", "hawaii_banned": "no", "eu_restricted_environmental": "yes",…
pediatric_safety
{"safe_for_newborn_0_6m": "avoid", "safe_for_infant_6_12m": "avoid", "safe_for_toddler_1_3y": "avoid", "safe_for_child_3_12y": "avoid", "safe_for_teen_12_18y": "caution", "pediatric_max_concentration_pct": "0.0", "adult_max_concentration_pct": "0.2", "pediatric_dermal_absorption_factor": "very high", "immature_skin_barrier_risk": "high", "oral_ingestion_risk": "high", "eye_irritation_risk": "high"…
pregnancy_detail
{"pregnancy_safe": "no", "breastfeeding_safe": "no", "trimester_restriction": "all", "risk_category": "not-rated", "reason": "Carcinogen; reproductive toxicant", "alternative_ingredient": "Formaldehyde-free preservatives", "source": "ACOG; IARC"}
regulatory
{"eu_status": "restricted", "us_status": "restricted", "eu_max_concentration": "0.002", "restricted_in": "max 0.2%, nail hardeners only up to 5%", "regulation_reference": "Annex III/13"}
skin_suitability
{"oily_skin": "avoid", "dry_skin": "avoid", "sensitive_skin": "avoid", "combination_skin": "avoid", "normal_skin": "avoid", "acne_prone": "avoid", "rosacea": "avoid", "eczema": "avoid", "hyperpigmentation": "avoid", "aging_mature": "avoid", "dehydrated": "avoid", "skin_benefit_primary": "preservative", "skin_benefit_secondary": "disinfectant", "mechanism_of_action": "Carcinogenic, severe allergen,…
PubChem Annotations
Safety and regulatory annotations from PubChem (NCBI) aggregated sources.
Safety (7)
Carcinogen Classification
1, carcinogenic to humans. (L135)
Source: Toxin and Toxin Target Database (T3DB)
Carcinogen Classification
Formaldehyde | Group 1: Carcinogenic to humans | Volume Sup 7: Overall Evaluations of Carcinogenicity: An Updating of IARC Monographs Volumes 1 to 42, 1987; 440 pages; ISBN 92-832-1411-0 (out of print) | Volume 62: (1995) Wood Dust and Formaldehyde | Volume 88: (2006) Formaldehyde, 2-Butoxyethanol and 1-tert-Butoxypropan-2-ol | Volume 100F: (2012) Chemical Agents and Related Occupations
Source: International Agency for Research on Cancer (IARC)
Evidence for Carcinogenicity
There is sufficient evidence in humans for the carcinogenicity of formaldehyde. Formaldehyde causes cancer of the nasopharynx and leukaemia. Also, a positive association has been observed between exposure to formaldehyde and sinonasal cancer. There is sufficient evidence in experimental animals for the carcinogenicity of formaldehyde. The Working Group was not in full agreement on the evaluation o
Source: Hazardous Substances Data Bank (HSDB)
Endocrine Disruptors
Potential endocrine disrupting compound
Source: NORMAN Suspect List Exchange
ICSC Safety Card
0275
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Adhesion/cohesion promoter
Binder
Biocide
Degradant/impurity
Insulators
Monomers
No specific technical function
Preservative
Regulatory List Membership (4)
California Proposition 65 (OEHHA)
EU Banned in Cosmetics
FDA Substances Added to Food (EAFUS)
EU CosIng Cosmetics Ingredient Database
Expert Verdict
Expert safety assessment and concern-level summary for Formaldehyde.
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
NOAEL Studies Summary
View details ->Public NOAEL study rows linked to Formaldehyde by CAS number or substance name.
Studies
21
Lowest NOAEL
10 mg/kg bw/day
Highest NOAEL
185 mg/kg bw/day
ToxValDB_ECHA_IUCLID
SCCS_vision_codex
COSMOS_DB
Known Synonyms
Caswell No. 465
EINECS 200-001-8
EPA Pesticide Chemical Code 043001
Formaldehyde, gas
Formalin 40
NCI-C02799
RCRA waste number U122
Aldehyd mravenci
Aldehyde formique
Aldeide formica
Formalin-loesungen
Oplossingen
UNII-1HG84L3525
Formalaz
Chlodithan
Chlodithane
Formalina
Formaline
Formol
Methylene glycol
Chemical Function
Biocide
Preservative
Binder
Insulators
Degradant/impurity
Regulatory Lists
drinking_water; Europe; manufacturing; plastic_additive
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
active_ingredient; Pesticides
Cross-Vertical Safety Context
Same-CAS public records found in pharmaceutical and food safety data.
SOURCE
ChEMBL / DrugCentral / FAERS
DB_PHARMA CAS match
Pharmaceutical Data
Same-CAS rows from the pharmaceutical spoke database.
Compound
FORMALDEHYDE
ChEMBL ID
CHEMBL1255
Max Phase
-1
SOURCE
EFSA / FDA GRAS
food_additives
Food Safety Data
Same-CAS food additive or FDA GRAS records from the core public database.
Food Name
Formaldehyde
ADI
0.15 mg/kg bw
Food Category
contaminants
Frequently Asked Questions
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 NOAEL for Formaldehyde?
The NOAEL (No Observed Adverse Effect Level) for Formaldehyde is 20 mg/kg bw/day based on a Short Term Toxicity study via oral route in rat. 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.
Is Formaldehyde used outside cosmetics?
Formaldehyde also appears in industrial chemical safety, pharmaceutical, and food safety data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Does Formaldehyde have different safety status in cosmetics vs industrial chemicals?
Formaldehyde is prohibited in EU cosmetics at max 2.2% but has active industrial GHS classifications (H301, H311, H314, H317, H318, H330, H331, H341).
Compliance Tools
Check Formaldehyde 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 multiple jurisdictions
MoS Calculator
Calculate Margin of Safety using SCCS methodology
Heavy Metal Limits
Compare limits across jurisdictions
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