Is Cuprous Oxide safe in cosmetics?
Cuprous Oxide has a safety rating of "POOR" in our database. EU status: prohibited. US status: permitted. 2 toxicological study endpoint(s) are available in our database.
Cuprous Oxide
Also known as: Copper oxide (Cu2O), Copper (1) oxide, Brown copper oxide, Caocobre, Caswell No. 266 (+15 more)
INCI: CUPROUS OXIDE
Cuprous Oxide (CAS 1317-39-1) is a cosmetic cosmetic ingredient functioning as Colorant (CI 77402); antimicrobial agent (primarily biocidal, not cosmetic). Reported NOAEL =78 mg/kg bw/day in Rat (ECHA); EU Regulation 1223/2009 status: prohibited; 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 data.
View industrial chemical safety profile for CAS 1317-39-1 →
Auto-generated CPSR Part A draft with source citations
Cross-Vertical Regulatory Divergence
Cuprous Oxide is prohibited in EU cosmetics but has active industrial GHS classifications (H302, H332, H318, H400, H410, H319, H335, H370).
Source: Cosmetics: ingredients.eu status; Chemicals: ghs classifications.signal word/hazard statement code
Function
Colorant (CI 77402); antimicrobial agent (primarily biocidal, not cosmetic)
Safety Rating
POOR
Chemistry & Identifiers
IUPAC Name
copper;oxocopper
InChIKey
BERDEBHAJNAUOM-UHFFFAOYSA-N
Regulatory Status
EU EU Status
prohibited
US US Status
permitted
US Notes
Not specifically FDA-listed for cosmetics; no CIR monograph. Used in antifouling paints (EPA-regulated), not cosmetics.
For full compliance data across multiple jurisdictions, use the Substance Compliance tool.
Safety Data
Margin of Safety, dermal absorption, and sensitization profile summaries for Cuprous Oxide.
Calculate MoS for your specific formulation with the MoS Calculator.
Toxicological Studies
2 study endpoints found for Cuprous Oxide. 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 | =78 mg/kg bw/day | oral | Rat | chronic | ECHA |
| NOAEL | =185 mg/kg bw/day | oral | Mouse | chronic | ECHA |
GHS Hazard Classification
Globally Harmonized System classification per ECHA C&L inventory and ILO/WHO International Chemical Safety Cards.
Signal Word
DANGER
Pictograms
Excl markWarnCorrEnviroAqua
Hazard Statements
Harmful if swallowed or if inhaled Causes serious eye damage 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 respiratory tract and digestive tract. Inhalation of fumes may cause metal fume fever. Exposure at high levels could cause kidneys and liver impairment. The effects may be delayed.
Long-term Exposure Effects
Lungs may be affected by repeated or prolongated exposure to dust particles.
Routes of Exposure
The substance can be absorbed into the body by inhalation and by ingestion.
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; Eye Dam. 1; Aquatic Acute 1; Aquatic Chronic 1
Hazard Statements
- H332 Harmful if inhaled
- H302 Harmful if swallowed
- H318 Causes serious eye damage
- H400 Very toxic to aquatic life
- H410 Very toxic to aquatic life with long lasting effects
Specific Concentration Limits / M-factors
inhalation: ATE = 3.34 mg/L dusts or mists; oral: ATE = 500.0 mg/kg bw; M = 100; M = 10
Inserted via ATP: ATP17
ECHA REACH Registration
European Chemicals Agency REACH dossier and Substances of Very High Concern listing.
Registration Type
Full
Tonnage Band
1,000 - 10,000 tonnes
Substance Type
SUBSTANCE
SVHC Candidate
No
Hazard classification: Restricted (Annex XVII)
PubChem Annotations
Safety and regulatory annotations from PubChem (NCBI) aggregated sources.
Safety (3)
Carcinogen Classification
No indication of carcinogenicity to humans (not listed by IARC).
Source: Toxin and Toxin Target Database (T3DB)
ICSC Safety Card
0421
Source: WHO/JECFA
Skin Eye Respiratory Irritation
Inhalation of copper fume results in the irritation of the upper respiratory tract. ... Contact with copper fumes will also cause irritation of the eyes, nose and throat. /Copper fumes/
Source: Hazardous Substances Data Bank (HSDB)
Function Categories & List Membership
Cosmetic/Chemical Function Categories
Softener and conditioner
Expert Verdict
Expert safety assessment and concern-level summary for Cuprous Oxide.
Regulatory Flags
colorant
NOAEL Studies Summary
View details ->Public NOAEL study rows linked to Cuprous Oxide by CAS number or substance name.
Studies
2
Lowest NOAEL
78 mg/kg bw/day
Highest NOAEL
185 mg/kg bw/day
ECHA
Known Synonyms
Copper oxide (Cu2O)
Copper (1) oxide
Brown copper oxide
Caocobre
Caswell No. 266
Copper hemioxide
Copper nordox
Copper oxide, red
Copper sardez
Copper-sandoz
CP Cuprous Oxide Pigment Grade
Cuprocide
Cuprous Oxide, AA Grade
Cuprous Oxide Type Two
EINECS 215-270-7
Fungi-rhap Cu-75
Kuprite
Oleo nordox
Oleocuivre
Oxyde cuivreux
Chemical Function
Softener and conditioner
Regulatory Lists
active_ingredient; Europe; Pesticides
active_ingredient; agricultural; applied; fruits_and_vegetables; Pesticides
active_ingredient; agricultural; applied; fruits_and_vegetables; Pesticides
active_ingredient; agricultural; applied; fruits_and_vegetables; 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
Australian Status
AICIS status: listed
Frequently Asked Questions
Is Cuprous Oxide allowed in the EU?
Cuprous Oxide EU regulatory status: prohibited. This is based on EU Regulation 1223/2009 and its amendments.
What does Cuprous Oxide do in cosmetics?
Cuprous Oxide functions as: Colorant (CI 77402); antimicrobial agent (primarily biocidal, not cosmetic). It is classified as a cosmetic ingredient in our database. CAS number: 1317-39-1.
What is the NOAEL for Cuprous Oxide?
The NOAEL (No Observed Adverse Effect Level) for Cuprous Oxide is =78 mg/kg bw/day based on a chronic study via oral route in Rat. A total of 2 study endpoints are available. Source: ECHA.
Is Cuprous Oxide classified as hazardous under GHS?
Cuprous Oxide carries a GHS signal word of "DANGER". Hazard statements: Harmful if swallowed or if inhaled Causes serious eye damage 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 Cuprous Oxide used outside cosmetics?
Cuprous Oxide also appears in industrial chemical safety data. The cross-vertical cards on this page render same-CAS public rows from the matched databases.
Does Cuprous Oxide have different safety status in cosmetics vs industrial chemicals?
Cuprous Oxide is prohibited in EU cosmetics but has active industrial GHS classifications (H302, H332, H318, H400, H410, H319, H335, H370).
Compliance Tools
Check Cuprous Oxide 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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