Is Bronopol safe in cosmetics?
Bronopol has a safety rating of "MODERATE" in our database. EU status: restricted. US status: restricted.
Bronopol
Also known as: 2-Bromo-2-nitro-1,3-propanediol, BRN 1705868, beta-Bromo-beta-nitrotrimethyleneglycol, Bronosol, Caswell No. 116A (+7 more)
INCI: BRONOPOL
Bronopol (CAS 52-51-7) is a cosmetic preservative functioning as Preservative. NOAEL 7 mg/kg bw/day (cross-referenced against ToxValDB ECHA IUCLID); EU Regulation 1223/2009 status: restricted, max 0.1%; 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 and pharmaceutical data.
View industrial chemical safety profile for CAS 52-51-7 →
Auto-generated CPSR Part A draft with source citations
Cross-Vertical Regulatory Divergence
Bronopol is classified GHS Danger (H301, H302, H312, H315, H318, H331, H335, H400) in the chemicals database but is restricted in EU cosmetics at max 0.1%.
Source: Cosmetics: ingredients.eu_status/eu_max; Chemicals: ghs_classifications.signal_word/hazard_statement_code
Function
Preservative
Safety Rating
MODERATE
Regulatory Status
EU EU Status
restricted
EU Max Conc.
0.1%
US US Status
restricted
US Notes
Washington State banned effective January 1, 2027 (August 2025 rule, WAC 246-930). No federal cosmetic concentration limit. CIR assessed safe at 0.01% or less in leave-on products and 0.1% or less in rinse-off products. Dual hazard: formaldehyde release and nitrosamine formation with secondary amines in formulation.
For full compliance data across multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Bronopol.
Calculate MoS for your specific formulation with the MoS Calculator.
GHS Hazard Classification
Globally Harmonized System classification per ECHA C&L inventory and ILO/WHO International Chemical Safety Cards.
Signal Word
DANGER
Pictograms
FlamFlameCorrExcl markWarnEnviroAqua
Hazard Statements
Flammable solid Harmful if swallowed or in contact with skin Causes skin irritation Causes serious eye damage May cause respiratory irritation Very toxic to aquatic life with long lasting effects
Short-term Exposure Effects
The substance is corrosive to the eyes. The substance is irritating to the skin and respiratory tract.
Long-term Exposure Effects
Repeated or prolonged contact may cause skin sensitization.
Routes of Exposure
The substance can be absorbed into the body by inhalation of its aerosol, through the skin and by ingestion.
Pre-Calculated Safety Assessment
Pre-calculated NOAEL → SED → MoS audit trail for Bronopol across SCCS product categories, with measured dermal absorption where available.
Sensitization Profile
Contact sensitization data for Bronopol based on clinical patch test studies and IFRA standards.
Sensitization Rate
low
Allergen Class
preservative
EU Allergen Listed
no
Patch Test Positive Rate
0.8%
Cross-reactivity Group
formaldehyde-releaser-group
Reaction Type
contact-dermatitis
Source: ESSCA 2019/20; IVDK; FDA
EU CLP Annex VI Harmonized Classification
Legally binding harmonized classification per Regulation (EC) No 1272/2008 (CLP) Annex VI.
Signal Word
Danger
Pictograms
Harmful / IrritantCorrosiveEnvironmental Hazard
Hazard Class and Category
Acute Tox. 4 *; Acute Tox. 4 *; STOT SE 3; Skin Irrit. 2; Eye Dam. 1; Aquatic Acute 1
Hazard Statements
- H312 Harmful in contact with skin
- H302 Harmful if swallowed
- H335 May cause respiratory irritation
- H315 Causes skin irritation
- H318 Causes serious eye damage
- H400 Very toxic to aquatic life
Specific Concentration Limits / M-factors
M = 10
Inserted via ATP: ATP01
Sensitization AOP Dashboard
Adverse Outcome Pathway data across 5 assays (DPRA, KeratinoSens, hCLAT, LLNA, NESIL) aggregated from public sources.
NESIL
1395 µg/cm²
GHS: 1B
Human: positive
Source: HPPT: [30] Marzulli FN and Maibach HI (1974): https://doi.org/10.1016/0015-6264(74)90367-8
HRIPT Human Patch Test Studies
2 human repeat insult patch tests aggregated from dermatological literature.
| Test Type | N | Sensitized | Dose µg/cm² | NESIL µg/cm² | Potency |
|---|---|---|---|---|---|
| HRIPT | - | 0 | 1395 | - | - |
| HRIPT | - | 0 | 3487.51 | - | - |
Endocrine Disruptor Evidence (Expanded)
Cross-referenced EDC classifications, mechanism data, and dose-response evidence from EDLists, SIN List, and cosmetic-specific detail sources.
Dose-Response Data Points
| Endpoint | Target | Value | Direction |
|---|---|---|---|
| ERα and AR receptor transactivation | ERα / AR | EC50/IC50: LOEC ~10 µM (estrogenic); no formal EC50 published; LOEC: 10 µM; NOEC: not established mixed | weak agonist (ER); possible weak AR agonist |
| AhR pathway activation (indirect/low potency) | AhR | EC50/IC50: No formal EC50; marginal activity in some studies at ≥50 µM; LOEC: ~50 µM (estimated); NOEC: not established mixed | weak indirect inducer (via oxidative stress) |
| Steroidogenesis (E2 / T production) | Steroidogenesis (CYP19 / 3βHSD) | EC50/IC50: LOEC ~50 µM (marginal steroidogenic effects at high concentrations); LOEC: ~50 µM (estimated); NOEC: not established mixed | weak modulator |
| Thyroid peroxidase enzyme activity inhibition | Thyroid peroxidase (TPO) | EC50/IC50: IC50 not formally reported; >30% inhibition at 100 µM (rat thyroid microsomes); LOEC: ~50 µM (estimated); NOEC: not determined mixed | inhibitor (via oxidative / halogenating species at high concentrations) |
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Full
Tonnage Band
100 - 1,000 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 V — Permitted Preservatives
Max: 0.1%
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.
KR Korea MFDS Annex 2 (Restricted)
Category: Preservative. Max: 0.1%. Amine-containing products prohibited
SA Saudi SFDA (V - Preservatives)
Max: 0.001.
JPKR Japan/Korea Cosmetics
Korea (Restricted): max 0.1%
BRIN Brazil/India Cosmetics
Brazil: Permitted Preservative · max 0,1%
India: Permitted Preservative · max 0.001
Additional Jurisdictional Restrictions (6)
| Jurisdiction | Status | Max % | Product Type |
|---|---|---|---|
| CN | permitted_preservative | 0.1 | Rinse-off products |
| CN | permitted_preservative | 0.1 | Rinse-off products |
| IN | permitted_preservative | 0.1 | all cosmetics |
| BR | permitted_preservative | 0.1 | Avoid nitrosamine formation |
| CA | restricted | 0.1% | All cosmetics except amine-containing formulations |
| ASEAN | permitted_preservative | 0.1% | All products |
Additional Ingredient Properties
2 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": "0.8", "sensitization_rate": "low", "common_reaction_type": "contact-dermatitis", "ifra_restricted": "no", "source": "ESSCA 2019/20; IVDK; FDA"}
deodorant
{"cas_number": "52-51-7", "ingredient_class": "antimicrobial_deodorant", "mechanism_of_action": "bacterial_growth_inhibition", "antiperspirant_efficacy_sweat_reduction_pct": "0", "deodorant_efficacy_hours": "24", "odor_reduction_pct": "60-80", "bacteriostatic": "yes", "bactericidal": "yes", "target_bacteria": "broad_spectrum", "microbiome_impact": "broad", "axillary_microbiome_effect": "varies by …
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Biocide
Deodorizer
No specific technical function
Preservative
Processing aids not otherwise specified
Regulatory List Membership (4)
EU Regulated in Personal Care
EU Restricted for Children (Cosmetics)
FDA Indirect Food Contact Additives
EU CosIng Cosmetics Ingredient Database
Expert Verdict
Expert safety assessment and concern-level summary for Bronopol.
Regulatory Flags
formaldehyde-releaser
nitrosamine-precursor
iarc-group-1-related
contact-allergen
preservative
washington-state-ban-2027
eu-restricted
annex-v
federal-ban-pending
children-restricted-eu
dual-hazard
endocrine_disruptor
eu_children_restricted
eu_cosing_listed
NOAEL Studies Summary
View details ->Public NOAEL study rows linked to Bronopol by CAS number or substance name.
Studies
24
Lowest NOAEL
7 mg/kg bw/day
Highest NOAEL
200 mg/kg bw/day
ECHA_REACH_reach_study_results_dossiers_23-05-2023.zip
Known Synonyms
2-Bromo-2-nitro-1,3-propanediol
BRN 1705868
beta-Bromo-beta-nitrotrimethyleneglycol
Bronosol
Caswell No. 116A
EINECS 200-143-0
EPA Pesticide Chemical Code 216400
Lexgard bronopol
Bronopolu
Bronopolum
UNII-6PU1E16C9W
1,2-Bromo-2-nitropropane-1,3-diol
Chemical Function
Preservative
Biocide
Processing aids not otherwise specified
Deodorizer
Regulatory Lists
children; Europe; Personal care - general moisturizing - hand/body lotion
children; Europe; Personal care - body hygiene - body wash
children; Europe; Personal care - hair styling and care - shampoo
children; Europe; Personal care - specialized bath products - bubble bath
children; Europe; Personal care
children; Europe; Personal care
children; Europe; Personal care
CEDI
Indirect additives food contact (10/2018)
fracking; water
Arts and crafts/Office supplies - general arts and crafts supplies - arts and crafts paint; Europe
Europe; Personal care - body hygiene - hand soap
active_ingredient; Pesticides
active_ingredient; Pesticides
Europe; Personal care - deodorant
Arts and crafts/Office supplies - general arts and crafts supplies - arts and crafts paint; Europe
consumer_product; Europe
active_ingredient; Pesticides
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
BRONOPOL
ChEMBL ID
CHEMBL1408862
Max Phase
2
Frequently Asked Questions
Is Bronopol allowed in the EU?
Bronopol EU regulatory status: restricted. Maximum allowed concentration: 0.1%. This is based on EU Regulation 1223/2009 and its amendments.
What does Bronopol do in cosmetics?
Bronopol functions as: Preservative. It is classified as a Preservative in our database. CAS number: 52-51-7.
Is Bronopol classified as hazardous under GHS?
Bronopol carries a GHS signal word of "DANGER". Hazard statements: Flammable solid Harmful if swallowed or in contact with skin Causes skin irritation Causes serious eye damage May cause respiratory irritation Very toxic to aquatic life with long lasting effects. 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 Bronopol used outside cosmetics?
Bronopol also appears in industrial chemical safety and pharmaceutical data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Does Bronopol have different safety status in cosmetics vs industrial chemicals?
Bronopol is classified GHS Danger (H301, H302, H312, H315, H318, H331, H335, H400) in the chemicals database but is restricted in EU cosmetics at max 0.1%.
Compliance Tools
Check Bronopol 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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Chemical family
Preservative (formaldehyde releaser)
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