Di-tert-butyl peroxide
The consolidated GB Cosmetics Regulation lists this record in Annex II.
Regulatory decision and full conditions
- Status
- Prohibited
- Legal role
- Binding rule
- Regulatory summary
- The consolidated GB Cosmetics Regulation lists this record in Annex II.
- Conditions and restrictions
- A prohibition entry may contain no separate condition text because the regulatory outcome is the prohibition itself. Open the cited source and apply the market-wide requirements below.
Substance identity
- Official source name
- Di-tert-butyl peroxide
- CAS
- 110-05-4
- EC
- 203-733-6
- Identity mapping
- standalone:official_gb_annex
Cross-market snapshot for this identity
Exact linked records currently present in this site. An absent market means no imported exact match, not permission to use the substance.
European Union
1 linked record
Open supporting recordGreat Britain
Current record1 linked record
Open supporting recordNew Zealand
1 linked record
Open supporting recordASEAN
1 linked record
Open supporting recordIndia
1 linked record · 1 with specific conditions
Open supporting recordSaudi Arabia
1 linked record
Open supporting recordVerified chemistry for CAS 110-05-4
Di-tert-butyl peroxide
- IUPAC name
- 2-tert-butylperoxy-2-methylpropane
- Molecular formula
- C8H18O2
- Molecular weight
- 146.23 g/mol
- Exact mass
- 146.130679813 Da
- Monoisotopic mass
- 146.130679813 Da
- XLogP3
- 2.1
- Topological polar surface area
- 18.5 Ų
- Molecular complexity
- 80.0
- Formal charge
- 0
- Hydrogen-bond donors
- 0
- Hydrogen-bond acceptors
- 2
- Rotatable bonds
- 3
- Heavy atoms
- 10
- Covalent units
- 1
Names and synonyms reported to PubChem
16 more reported names
External database identifiers
Advanced structure statistics
- Defined atom stereocentres
- 0
- Undefined atom stereocentres
- 0
- Defined bond stereocentres
- 0
- Undefined bond stereocentres
- 0
- 3D pharmacophore features
- 2
- 3D rings
- 0
- 3D hydrophobes
- 2
- 3D acceptor features
- 0
- 3D donor features
- 0
- 3D anionic centres
- 0
- 3D cationic centres
- 0
- 3D conformers
- 2
- Effective 3D rotors
- 3.0
Machine-readable structure identifiers
- SMILES
CC(C)(C)OOC(C)(C)C- InChI
InChI=1S/C8H18O2/c1-7(2,3)9-10-8(4,5)6/h1-6H3- InChIKey
LSXWFXONGKSEMY-UHFFFAOYSA-N
Evidence from additional scientific databases
NIH PubChem PUG-View
Attributed physical-property, hazard, environmental and use annotations.
- Boiling Point: 232 °F at 760 mmHg (NTP, 1992) Source: CAMEO Chemicals
- Boiling Point: 111 °C Source: Hazardous Substances Data Bank (HSDB)
- Boiling Point: 111 °C @760 [mm Hg] Source: PAC Chemical Database, U.S. Department of Energy
- Color/Form: Clear, water-white liquid Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: Liquid at 20 °C Source: Hazardous Substances Data Bank (HSDB)
- Color/Form: Yellow liquid Source: Hazardous Substances Data Bank (HSDB)
- Density: 0.704 at 68 °F (NTP, 1992) - Less dense than water; will float Source: CAMEO Chemicals
- Density: 0.7910 at 25 °C/25 °C Source: Hazardous Substances Data Bank (HSDB)
- Density: Relative density (water = 1): 0.8 Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Density: 0.791 @25 °C Source: PAC Chemical Database, U.S. Department of Energy
- Flash Point: 65 °F (NTP, 1992) Source: CAMEO Chemicals
- Flash Point: 1 °C (34 °F) - closed cup Source: Hazardous Substances Data Bank (HSDB)
- Flash Point: 65 °F (18 °C) - open cup Source: Hazardous Substances Data Bank (HSDB)
- Flash Point: 12 °C - closed cup Source: Hazardous Substances Data Bank (HSDB)
- Flash Point: 12 °C c.c. Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- LogP: log Kow = 3.2 at 22 °C, pH 7.2 Source: Hazardous Substances Data Bank (HSDB)
- LogP: 1-4 Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Melting Point: -40 °F (NTP, 1992) Source: CAMEO Chemicals
- Melting Point: -40 °C Source: Hazardous Substances Data Bank (HSDB)
- Melting Point: MP: -29 °C Source: Hazardous Substances Data Bank (HSDB)
- Melting Point: -40 °C Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Melting Point: -40 °C Source: PAC Chemical Database, U.S. Department of Energy
- Physical Description: Di-tert-butyl peroxide is a clear colorless liquid. (NTP, 1992) Source: CAMEO Chemicals
- Physical Description: CBI; Liquid Source: EPA Chemical Data Reporting (CDR)
- Physical Description: Clear, water-white or yellow liquid; Insoluble in water; [HSDB] Faintly yellow clear liquid; Insoluble in water; [MSDSonline] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Physical Description: COLOURLESS-TO-YELLOW LIQUID WITH CHARACTERISTIC ODOUR. Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Refractive Index: Index of refraction: 1.3890 @ 20 °C/D Source: Hazardous Substances Data Bank (HSDB)
- Solubility: less than 1 mg/mL at 70 °F (NTP, 1992) Source: CAMEO Chemicals
- Solubility: In water, 100 mg/L at 25 °C Source: Hazardous Substances Data Bank (HSDB)
- Solubility: In water, 1.71 mg/L at 20 °C, pH 8.1 Source: Hazardous Substances Data Bank (HSDB)
- Solubility: Insoluble in water Source: Hazardous Substances Data Bank (HSDB)
- Solubility: Soluble in styrene, ketones, most aliphatic and aromatic hydrocarbons Source: Hazardous Substances Data Bank (HSDB)
- Solubility: For more Solubility (Complete) data for Bis(1,1-dimethylethyl)peroxide (6 total), please visit the HSDB record page. Source: Hazardous Substances Data Bank (HSDB)
- Solubility: Solubility in water: none Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Vapor Pressure: 19.51 mmHg at 68 °F (NTP, 1992) Source: CAMEO Chemicals
- Vapor Pressure: 25.1 [mmHg] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Vapor Pressure: 25.1 mm Hg at 25 °C /calculated from experimentally derived coefficients/ Source: Hazardous Substances Data Bank (HSDB)
- Vapor Pressure: Vapor pressure, kPa at 20 °C: 2.6 Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- Vapor Pressure: 25.1 [mm Hg] @25 °C Source: PAC Chemical Database, U.S. Department of Energy
- Exposure Routes: The substance can be absorbed into the body by inhalation of its vapour. Source: ILO-WHO International Chemical Safety Cards (ICSCs)
- First Aid: EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.; SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.; INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) shou Source: CAMEO Chemicals
- Signal: Danger Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
- GHS Hazard Statements: H225: Highly Flammable liquid and vapor [Danger Flammable liquids]; H242: Heating may cause a fire [Danger Self-reactive substances and mixtures; Organic peroxides]; H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity] Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
- Precautionary Statement Codes: P203, P210, P233, P234, P235, P240, P241, P242, P243, P280, P303+P361+P353, P318, P370+P378, P403, P403+P235, P405, P410, P411, P420, and P501 (click each P-code to see the statement) Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
- Signal: Danger Source: European Chemicals Agency (ECHA)
- GHS Hazard Statements: H225 (> 99.9%): Highly Flammable liquid and vapor [Danger Flammable liquids]; H242 (> 99.9%): Heating may cause a fire [Danger Self-reactive substances and mixtures; Organic peroxides]; H319 (35.6%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H334 (14.1%): May cause allergy or asthma symptoms or breathing difficulties if inhaled [Danger Sensitization, respiratory]; H341 (62.5%): Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H412 (11.3%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard] Source: European Chemicals Agency (ECHA)
- Precautionary Statement Codes: P203, P210, P233, P234, P235, P240, P241, P242, P243, P260, P264+P265, P271, P273, P280, P284, P303+P361+P353, P304+P340, P305+P351+P338, P318, P337+P317, P342+P316, P370+P378, P403, P403+P235, P405, P410, P411, P420, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
- ECHA C&L Notifications Summary: Aggregated GHS information provided per 1252 reports by companies from 14 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website. Source: European Chemicals Agency (ECHA)
- Signal: Danger Source: NITE-CMC
- GHS Hazard Statements: H225: Highly Flammable liquid and vapor [Danger Flammable liquids]; H242: Heating may cause a fire [Danger Self-reactive substances and mixtures; Organic peroxides]; H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H402: Harmful to aquatic life [Hazardous to the aquatic environment, acute hazard] Source: NITE-CMC
- Precautionary Statement Codes: P203, P210, P233, P234, P235, P240, P241, P242, P243, P273, P280, P303+P361+P353, P318, P370+P378, P403, P403+P235, P405, P410, P411, P420, and P501 (click each P-code to see the statement) Source: NITE-CMC
- Signal: Warning Source: NITE-CMC
- GHS Hazard Statements: H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity] Source: NITE-CMC
- NFPA Health Rating: 3 - Materials that, under emergency conditions, can cause serious or permanent injury. Source: Hazardous Substances Data Bank (HSDB)
- NFPA Fire Rating: 2 - Materials that must be moderately heated or exposed to relatively high ambient temperatures before ignition can occur. Materials would not under normal conditions form hazardous atmospheres with air, but under high ambient temperatures or under moderate heating could release vapor in sufficient quantities to produce hazardous atmospheres with air. Source: Hazardous Substances Data Bank (HSDB)
- NFPA Instability Rating: 4 - Materials that in themselves are readily capable of detonation or explosive decomposition or explosive reaction at normal temperatures and pressures. Source: Hazardous Substances Data Bank (HSDB)
- NFPA Specific Notice: OX - Oxidizer: Materials that possess oxidizing properties. Source: Hazardous Substances Data Bank (HSDB)
- Toxicity Summary: IDENTIFICATION AND USE: Bis(1,1-dimethylethyl) peroxide is a liquid. It is used as a polymerization catalyst for resins, including olefins, styrene, styrenated alkyds, and silicones. It is also used as an ignition accelerator for diesel fuel, and an organic synthesis intermediate. HUMAN STUDIES: Workers engaged in the production of organic peroxides suffered from grippe, angina, acute respiratory diseases, and pneumonia. ANIMAL STUDIES: Tumorigenic response after exposure of di-tert-butyl peroxide at a single dose of 100 umol to 50 mice consisted of 7 animals with malignant lymphomas and 1 animal with pulmonary adenomas out of 35 survivors. Di-t-butyl peroxide, which was essentially inactive in short-term in vitro promotion assays, was also totally inactive in promoting papillomas or carcinomas in initiated skin. Chromosome breakage has been detected using tert-butyl peroxide. The mutagenicity of di-t-butyl peroxide was tested using Salmonella typhimurium TA 98 and TA 100 in the presence of metabolic activation. No mutagenic activity was observed with di-t-butyl peroxide. Source: Hazardous Substances Data Bank (HSDB)
- Environmental Bioconcentration: An estimated BCF of 88 was calculated in fish for bis(1,1-dimethylethyl)peroxide(SRC), using an estimated log Kow of 3.45(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Source: Hazardous Substances Data Bank (HSDB)
- Environmental Fate: TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 620(SRC), determined from a structure estimation method(2), indicates that bis(1,1-dimethylethyl)peroxide is expected to have moderate mobility in soil(SRC). Volatilization of bis(1,1-dimethylethyl)peroxide from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 0.0483 atm-cu m/mole(SRC), based upon its vapor pressure, 25.1 mm Hg(3), and water solubility, 100 mg/L(4). Bis(1,1-dimethylethyl)peroxide is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). Utilizing the Japanese MITI test, 0% of the Theoretical BOD was reached in 4 weeks(4) indicating that biodegradation is not an important environmental fate process in soil(SRC). Organic peroxides, such as bis(1,1-dimethylethyl)peroxide, are strong oxidizers and may ignite organic materials in soil on contact(6). Source: Hazardous Substances Data Bank (HSDB)
- Environmental Fate: AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 620(SRC), determined from a structure estimation method(2), indicates that bis(1,1-dimethylethyl)peroxide is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 0.0483 atm-cu m/mole(SRC), derived from its vapor pressure, 25.1 mm Hg(4), and water solubility, 100 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 4 hrs and 5 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 88(SRC), from an estimated log Kow of 32.45(2), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Utilizing the Japanese MITI test, 0% of the Theoretical BOD was reached in 4 weeks(7) indicating that biodegradation is not an important environmental fate process in water(SRC). Organic peroxides, such as bis(1,1-dimethylethyl)peroxide, are strong oxidizers and may ignite organic materials in water on contact(8). Source: Hazardous Substances Data Bank (HSDB)
- Environmental Fate: ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), bis(1,1-dimethylethyl)peroxide, which has a vapor pressure of 25.1 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase bis(1,1-dimethylethyl)peroxide is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 15 days(SRC), calculated from its rate constant of 1.0X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Bis(1,1-dimethylethyl)peroxide absorbs UV light at wavelengths of 340 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC). Source: Hazardous Substances Data Bank (HSDB)
- Consumer Uses: Catalyst; Not Known or Reasonably Ascertainable Source: EPA Chemical Data Reporting (CDR)
- Industry Uses: Polymerization promoter; Solvent; CBI; Plasticizer; Catalyst; Intermediate Source: EPA Chemical Data Reporting (CDR)
- Sources/Uses: Used as an initiator for high-temperature, high-pressure polymerizations of ethylene and halogenated ethylenes; in the synthesis of polyketones; as a finishing catalyst for polystyrene; as a polymerization catalyst for acrylonitrile polymers and resins (including olefins, styrene, styrenated alkyds, and silicones); as curing agent for styrenated alkyds and silicone rubbers; as ignition accelerator for diesel fuels; and as a cross-linking agent (rubber and resins); [HSDB] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Industrial Processes with risk of exposure: Petroleum Production and Refining [Category: Industry]; Plastic Composites Manufacturing [Category: Industry] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
- Uses: Polymerization catalyst for resins, including olefins, styrene, styrenated alkyds, and silicones; ignition accelerator for diesel fuel; organic synthesis; intermediate. Source: Hazardous Substances Data Bank (HSDB)
- Uses: Cross-linking agent (rubber, resins) Source: Hazardous Substances Data Bank (HSDB)
- Uses: POLYMERIZATION CATALYST/INITIATOR FOR POLYETHYLENE Source: Hazardous Substances Data Bank (HSDB)
- Uses: IGNITION ACCELERATOR FOR DIESEL FUELS Source: Hazardous Substances Data Bank (HSDB)
Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record
Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.
Additional source coverage and match status
| Source | Result | Checked |
|---|---|---|
| NIH PubChem PUG-View | Exact match | 2026-08-31 |
A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.
Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.
Official source and provenance
- Registered source
- Great Britain Cosmetics Regulation — consolidated Annexes II–VI and amendments
- Source reference
- GB Cosmetics Regulation, Annex II, entry 1553
- Source record ID
II-1553- Source version
- 2026-08-15
- Source language
- English
- Translation status
- Original is English
- Effective date
- 2026-08-15
- Source updated
- 2026-08-19
- Snapshot checked
- 2026-08-30 04:51 UTC
- Validation method
- legislation.gov.uk XML table parse; {'II': 1758, 'III': 326, 'IV': 154, 'V': 57, 'VI': 34}
- SHA-256
e3a386d950f54c6e7a7f9e784d1bd46e52de725137e89d5630709824475215d8
Registered dataset notes
- Dataset coverage
- Complete consolidated GB Annexes II–VI, with later amendments versioned separately
- Authority note
- Binding GB schedules and versioned amendments to retained Regulation 1223/2009; applies to England, Wales and Scotland, not Northern Ireland
- Source licence
- Open Government Licence v3.0 / Crown copyright
- Attribution
- Contains public sector information licensed under the Open Government Licence v3.0.
How this record fits the market dataset
Status distribution
Condition text is present on 517 of 2329 current records. An empty condition field is interpreted according to the record type above; it is never converted into an unrestricted-use claim.
Great Britain market context
Complete consolidated annex dataset
Coverage version: GB retained Regulation 1223/2009 schedules, effective 15 August 2026
Current consolidated Annexes II–VI for England, Scotland and Wales.
Verification checklist
- Confirm INCI/CAS/EC identity.
- Review every current GB Annex II–VI match.
- Check commencement dates and later statutory instruments.
- Verify SCPN, responsible-person, safety-report and labelling duties.
Official market sources
- Great Britain Cosmetics Regulation — consolidated Annexes II–VI and amendmentsBinding GB schedules and versioned amendments to retained Regulation 1223/2009; applies to England, Wales and Scotland, not Northern Ireland
Verification workflow and record completeness
Before using this result in a compliance decision
- Confirm that “Di-tert-butyl peroxide” and every CAS/EC identifier refer to the material in your supplier specification.
- Confirm INCI/CAS/EC identity.
- Review every current GB Annex II–VI match.
- Check commencement dates and later statutory instruments.
- Verify SCPN, responsible-person, safety-report and labelling duties.
- Document the source version and recheck the regulator before manufacture, notification or market placement.
Fields available in this record
- Official substance nameAvailable
- CASAvailable
- ECAvailable
- Separate condition textNot present in source row
- Effective dateAvailable
- Snapshot hash and methodAvailable
Questions this page answers
Stable citation
Di-tert-butyl peroxide. GB Cosmetics Regulation, Annex II, entry 1553. Great Britain. Source version 2026-08-15. CosIng Checker regulatory record: https://cosingchecker.com/regulations/gb/records/5908/
Cite the regulator as the legal authority. This page is a structured evidence index and verification aid, not a substitute for the official text or professional legal assessment.
Interpretation and limits for Great Britain
This official record identifies the substance as prohibited for cosmetic use in the stated market scope.
Do not rely on a formulation containing this identity until the cited source, effective date and exact substance match have been verified.
How to interpret the legal role
The cited row forms part of a binding rule or legally incorporated list for this market.
Evidence on this page
- Recorded outcome: Prohibited
- Legal role: Binding rule
- Source version: 2026-08-15
- Effective date: 2026-08-15
What it does not prove
No annex match is not approval and does not cover Northern Ireland, which follows the applicable EU framework.
Further authoritative substance research
These sources can add identity, safety, exposure or hazard context. A link is not evidence that the database contains this exact substance, and none of these sources overrides the market decision above.
Cosmetic Ingredient Review safety assessments
Expert Panel conclusions, assessed ingredient groups, use conditions, dates and report documents
Independent expert review considered by FDA; not a government approval or binding market rule
Research this identity at the sourceFDA Global Substance Registration System
UNII identifiers, preferred names, substance types, codes and public substance relationships
Identity registry only; UNII availability does not imply FDA review or approval
Research this identity at the sourceILO/WHO International Chemical Safety Cards
Hazards, symptoms, first aid, storage, incompatibilities and physical properties for covered chemicals
International occupational chemical-safety reference; not cosmetic-use approval
Research this identity at the sourceJapan NITE-CHRIP
Chemical identity, Japanese and foreign legal lists, GHS hazards and exposure-related information
Chemical-management evidence; cosmetic status remains governed by the applicable MHLW standard and market rules
Research this identity at the sourceNIOSH Pocket Guide to Chemical Hazards
REL, PEL, IDLH, properties, exposure routes, symptoms, target organs, first aid and measurement methods for covered workplace chemicals
US occupational-health guidance and limits; not a cosmetic ingredient decision
Research this identity at the sourceOECD eChemPortal
Gateway to authority-owned physical-property, fate, ecotoxicity, toxicity, exposure and GHS records
Discovery gateway; each linked authority remains responsible for its data
Research this identity at the sourceUS EPA CompTox CTX APIs
API key required for importDTXSID identity, experimental and predicted properties, toxicity, bioactivity, exposure and environmental data
Scientific and computational evidence; predictions must remain labelled and do not determine cosmetic legality
Research this identity at the source