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Annex II Entry 400 CMR15/10/2010

1,2-Epoxybutane

1,2-Epoxybutane is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.

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Prohibited substance— Annex II, EU Regulation 1223/2009
Entry: 400
CMR

Chemical identity and properties

PubChem 2D chemical structure for CAS 106-88-7
CAS 106-88-7PubChem CID 7834

1,2-Epoxybutane

1,2-Epoxybutane is an epoxide. — ChEBI

IUPAC name
2-ethyloxirane
Molecular formula
C4H8O
Molecular weight
72.11 g/mol
Exact mass
72.057514874 Da
XLogP3
0.8
Topological polar surface area
12.5 Ų
Hydrogen-bond donors
0
Hydrogen-bond acceptors
1
Covalent units
1
Defined stereocentres
0

Also known as

1,2-Butylene oxideEthyloxiraneOxirane, ethyl-Ethylethylene oxide1,2-Butene oxide1-BUTENE OXIDE1-Butylene oxide1,2-Monoepoxybutane
16 more reported names
Ethylene oxide, ethyl-Butane, 1,2-epoxy-alpha-Butylene oxideDL-1,2-Epoxybutanen-Butene-1,2-oxideEthyl ethylene oxideNCI-C55527(+-)-2-Ethyloxirane(+-)-EthyloxiraneFR67H5388ONSC-24240BUTENE 1,2-EPOXIDE1,2-BUTYLENE EPOXIDERefChem:72057203-438-2Epoxybutane
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

Evidence from additional scientific databases

EMBL-EBI ChEBI
Exact identifier matchCHEBI:82326

1,2-Epoxybutane

Formula
C4H8O
Average mass
72.107 g/mol
Monoisotopic mass
72.05751 Da
Formal charge
0
  • epoxide — is a (CHEBI:32955)
  • epoxide — is a (CHEBI:32955)
Additional curated names
1-Butene oxide
Cross-references from this source
  • CAS: 106-88-7 — KEGG COMPOUND
  • MANUAL_X_REF: C19237 — KEGG COMPOUND

Mapped by: Exact CAS cross-reference in the ChEBI compound record. Source updated: 2026-08-13. Retrieved: 2026-08-31. Open source record

NIH PubChem PUG-View
Exact identifier match7834

Attributed physical-property, hazard, environmental and use annotations.

  • Physical Description: 1,2-butylene oxide appears as a clear colorless volatile liquid with an ethereal odor. Flash point near 0 °F. Density about 6.9 lb / gal. Soluble in water. Boiling point near 140 °F. Flammable over a wide range of vapor-air concentrations. May polymerize with the evolution of heat and possible rupture of container if contaminated. Vapors irritate eyes, skin and respiratory system. Prolonged contact with skin may cause in delayed burns. Vapors are heavier than air. Used as an intermediate to make various polymers. Chemicals that polymerize are often stabilized by refrigeration. Source: CAMEO Chemicals
  • Physical Description: Liquid Source: EPA Chemical Data Reporting (CDR)
  • Physical Description: Colorless liquid with a characteristic odor; [ICSC] Colorless liquid with an unpleasant odor; May decompose on exposure to moisture; [MSDSonline] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
  • Physical Description: COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR. 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. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.; INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. IMMEDIATELY call a physician and be prepared to transport the victim to a hospital even if no symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop. Provide proper respiratory protection to rescuers entering an unknow Source: CAMEO Chemicals
  • ERG2024, Guide 127P (1,2-Butylene oxide, stabilized): General First Aid:; · Call 911 or emergency medical service.; · Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.; · Move victim to fresh air if it can be done safely.; · Administer oxygen if breathing is difficult.; · If victim is not breathing:; -- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.; -- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).; -- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.; · Remove and isolate contaminated clothing and shoes.; · For minor skin contact, avoid spreading material on unaffected skin.; · In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.; · For severe burns, immediate medical attention is required.; · Effects of exposure (inhalation, ingestion, Source: Emergency Response Guidebook (ERG)
  • 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]; H302: Harmful if swallowed [Warning Acute toxicity, oral]; H312: Harmful in contact with skin [Warning Acute toxicity, dermal]; H315: Causes skin irritation [Warning Skin corrosion/irritation]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H332: Harmful if inhaled [Warning Acute toxicity, inhalation]; H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H351: Suspected of causing cancer [Warning Carcinogenicity] Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
  • Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P317, P318, P319, P321, P330, P332+P317, P337+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement) Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
  • Note: This chemical does not meet GHS hazard criteria for < 0.1% (1 of 1001) of reports. Source: European Chemicals Agency (ECHA)
  • Signal: Danger Source: European Chemicals Agency (ECHA)
  • GHS Hazard Statements: H225 (> 99.9%): Highly Flammable liquid and vapor [Danger Flammable liquids]; H302 (> 99.9%): Harmful if swallowed [Warning Acute toxicity, oral]; H312 (> 99.9%): Harmful in contact with skin [Warning Acute toxicity, dermal]; H315 (> 99.9%): Causes skin irritation [Warning Skin corrosion/irritation]; H319 (> 99.9%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H332 (99.6%): Harmful if inhaled [Warning Acute toxicity, inhalation]; H335 (> 99.9%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H351 (> 99.9%): Suspected of causing cancer [Warning Carcinogenicity]; H412 (47.1%): 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, P240, P241, P242, P243, P261, P264, P264+P265, P270, P271, P273, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P317, P318, P319, P321, P330, P332+P317, P337+P317, P362+P364, P370+P378, P403+P233, P403+P235, P405, 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 1001 reports by companies from 18 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Reported as not meeting GHS hazard criteria per 1 of 1001 reports by companies.; There are 17 notifications provided by 1000 of 1001 reports by companies with hazard statement code(s).; 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]; H302: Harmful if swallowed [Warning Acute toxicity, oral]; H312: Harmful in contact with skin [Warning Acute toxicity, dermal]; H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]; H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]; H331: Toxic if inhaled [Danger Acute toxicity, inhalation]; H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H336: May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]; H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H351: Suspected of causing cancer [Warning Carcinogenicity]; H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure] Source: NITE-CMC
  • Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P260, P261, P264, P264+P265, P270, P271, P280, P301+P317, P301+P330+P331, P302+P352, P302+P361+P354, P303+P361+P353, P304+P340, P305+P354+P338, P316, P317, P318, P319, P321, P330, P362+P364, P363, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
  • GHS Hazard Statements: H402: Harmful to aquatic life [Hazardous to the aquatic environment, acute hazard] 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: 3 - Liquids and solids that can be ignited under almost all ambient temperature conditions. Materials produce hazardous atmospheres with air under almost all ambient temperatures or, though unaffected by ambient temperatures, are readily ignited under almost all conditions. Source: Hazardous Substances Data Bank (HSDB)
  • NFPA Instability Rating: 2 - Materials that readily undergo violent chemical changes at elevated temperatures and pressures. Source: Hazardous Substances Data Bank (HSDB)
  • NFPA Specific Notice: W - No water: Materials that react violently or explosively with water. Source: Hazardous Substances Data Bank (HSDB)
  • Toxicity Summary: IDENTIFICATION AND USE: 1-Butene oxide is a colorless liquid with a pungent, disagreeable, sweetish odor, somewhat like butyric acid. It is used as an intermediate, for various polymers, a stabilizer for chlorinated solvents, and a corrosion inhibitor. 1-Butene oxide is also used as an acid scavenger for chlorine-containing materials such as trichloroethylene and to react with ammonia to produce alkanolamines. HUMAN EXPOSURE AND TOXICITY: 1-Butene oxide is possibly carcinogenic to humans (Group 2B). ANIMAL STUDIES: 1-Butene oxide was irritating to the eyes. Irritating effects to the skin were severe (corrosion) if evaporation was minimized due to occlusive application, but there was no effect by semi-occlusive application. It was not sensitizing in a guinea pig maximization test. In 90-day inhalation studies with rats and mice 1-butene oxide mainly caused nasal lesions. Systemic effects occurred at higher concentrations (rat 2400 mg/cu m: decreased mean body weight gain; mice 2400 mg/cu m: e.g. renal tubular necrosis). There is clear evidence for 1-butene oxide being a locally acting carcinogen in male rats (inhalation of 600 mg/cu m caused no tumors and 1,200 mg/cu m caused neopla Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Bioconcentration: An estimated BCF of 3 was calculated in fish for 1-butene oxide(SRC), using a log Kow of 0.68(1) and a regression-derived equation(2). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC). Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Fate: TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 10(SRC), determined from a structure estimation method(2), indicates that 1-butene oxide is expected to have very high mobility in soil(SRC). Volatilization of 1-butene oxide from moist soil surfaces is expected to be an important fate process(SRC), given an estimated Henry's Law constant of 1.70X10-4 atm-cu m/mole(SRC), based upon its vapor pressure, 170 mm Hg(3), and its water solubility, 95,500 mg/L(4). 1-Butene oxide is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure. A 100% of theoretical BOD using activated sludge in the Japanese MITI test(5) suggests that biodegradation is an important environmental fate process in soil(SRC). Results of various biodegradation screening tests suggest that 1-butene oxide is readily biodegradable(3). 1-Butene oxide has an aqueous hydrolysis half-life of about 6.5 days at pH 7 and 25 °C(3,4); therefore, hydrolysis may be an important fate process in moist soils(SRC). Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Fate: AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 10(SRC), determined from a structure estimation method(2), indicates that 1-butene oxide is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a estimated Henry's Law constant of 1.7X10-4 atm-cu m/mole(SRC) derived from its vapor pressure, 170 mm Hg(4), and its water solubility, 95,500 mg/L(4). Using this Henry's Law constant and an estimation method(2), volatilization half-lives for a model river and model lake are 6.9 hours and 4.7 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 3(SRC), from its log Kow of 0.68(3) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). A 100% of theoretical BOD using activated sludge in the Japanese MITI test(6) suggests that biodegradation is an important environmental fate process in water(SRC). Results of various biodegradation screening tests suggest that 1-butene oxide is readily biodegradable(3). The epoxides (such as butene oxide) degrade in water by hydrolysis and related ionic reactions to glyco 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), 1-butene oxide, which has a vapor pressure of 170 mm Hg at 24 °C(2), is expected to exist solely as a vapor in the ambient atmosphere(SRC). Vapor-phase 1-butene oxide is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is 8.4 days(SRC), calculated from its rate constant of 1.91X10-12 cu cm/molecule-sec at 25 °C(3). Epoxides, such as 1-butene oxide, may be formed in the ambient atmosphere via reaction of alkenes with various atmospheric oxidants(4). 1-Butene oxide may react with tropospheric aerosols and water to yield 1,2-butanediol through hydrolysis, especially under acidic conditions(4). 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
SourceResultChecked
EMBL-EBI ChEBIExact match2026-08-31
NIH PubChem PUG-ViewExact match2026-08-31

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.

Record details

Chemical name

1,2-Epoxybutane

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

CMR

CategoryCarcinogenicMutagenicReprotoxic
Cat. 2✓——

Key data

CAS
106-88-7
EC
203-438-2
Annex
II
Entry number
400

Direct matches are limited for this record, so nearby entries from Annex II are shown as well.

Annex II 399
Nearby record in the same annex

Lidocaine (INN)

CAS: 137-58-6
EC: 205-302-8

What Annex II means for 1,2-Epoxybutane

1,2-Epoxybutane is listed as a prohibited substance under Annex II of EU Cosmetics Regulation 1223/2009 and must not be intentionally added. Article 17 separately addresses unintended small quantities that are technically unavoidable under good manufacturing practice and compatible with the Article 3 safety requirement.

Formulators must screen their ingredients and raw materials to ensure none contain this substance. Suppliers should provide documentation confirming absence when requested.

The page also surfaces 12 related annex records with overlapping identifiers, annex logic or naming patterns.

Compliance checklist

  • Verify this substance is absent from all raw materials and finished formulations.
  • Request absence confirmation or CoA from raw material suppliers.
  • Document the screening result in the Product Information File (PIF).
  • This substance has CMR classification. Review the CMR table above and verify current Annex II/III status before use.

Frequently asked questions

Yes. 1,2-Epoxybutane is listed in Annex II of EU Cosmetics Regulation 1223/2009 and is prohibited as an intentionally added cosmetic ingredient. Article 17 provides a narrow exception for unintended small quantities that are technically unavoidable under good manufacturing practice, provided the product remains safe under Article 3.

CAS 106-88-7 is the unique numerical identifier assigned to 1,2-Epoxybutane by the Chemical Abstracts Service. In cosmetic compliance work, the CAS number is used to cross-reference the substance across regulatory databases, raw material specifications and safety assessment reports. Multiple EU annex entries may share the same CAS number if the same substance appears under different conditions or in different annexes.

1,2-Epoxybutane has a CMR (carcinogenic, mutagenic or reprotoxic) classification under EU CLP Regulation. Under Article 15 of EU Cosmetics Regulation 1223/2009, CMR substances of category 1A or 1B are prohibited in cosmetics unless specifically permitted. Category 2 CMR substances may be used only if assessed safe by the SCCS. Always verify current annex status and any applicable derogations before use.

Use the INCI Checker tool on this site to paste your full ingredient list (INCI) and scan it against all Annex II–VI entries. The tool highlights any ingredients that match restricted, prohibited or allergen-flagged records. This is useful for rapid compliance screening of finished product formulas or raw material declarations.
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Source note for Annex II record 1,2-Epoxybutane

This page summarizes one Annex II record for 1,2-Epoxybutane from public European Commission cosmetic materials and adds linked inventory or identifier matches when available.

Use this record page to review Annex II conditions for 1,2-Epoxybutane, but confirm any final regulatory decision against the current official annex wording and source files.

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