Skip to main content
CosIng Checker
CosIng Checker
EU cosmetic ingredients, restrictions and safety
Login
Annex II Entry 1689 CMR11/11/2022

4-methylpentan-2-one; isobutyl methyl ketone (MIBK)

4-methylpentan-2-one; isobutyl methyl ketone (MIBK) is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.

Search similar Back to annex Compare
Prohibited substance— Annex II, EU Regulation 1223/2009
Entry: 1689
CMR

Chemical identity and properties

PubChem 2D chemical structure for CAS 108-10-1
CAS 108-10-1PubChem CID 7909

Methyl Isobutyl Ketone

Methyl isobutyl ketone is a ketone. — ChEBI

IUPAC name
4-methylpentan-2-one
Molecular formula
C6H12O
Molecular weight
100.16 g/mol
Exact mass
100.088815002 Da
XLogP3
1.3
Topological polar surface area
17.1 Ų
Hydrogen-bond donors
0
Hydrogen-bond acceptors
1
Covalent units
1
Defined stereocentres
0

Also known as

4-Methyl-2-pentanoneIsopropylacetoneIsobutyl methyl ketoneHexoneMIBK2-Pentanone, 4-methyl-2-Methyl-4-pentanoneShell mibk
16 more reported names
4-Methyl-2-oxopentaneMethylisobutylketonIsohexanoneHexonMetilisobutilchetoneMetyloizobutyloketonIsobutyl-methylketon2-Methylpropyl methyl ketoneIsopropyl acetoneMethyl-isobutyl-cetone4-Methyl-2-pentanon4-Metilpentan-2-oneKetone, isobutyl methyl4-Methyl-pentan-2-onFEMA No. 2731Rcra waste number U161
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

Evidence from additional scientific databases

NIH PubChem PUG-View
Exact identifier match7909

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

  • 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
  • ERG2024, Guide 127 (Methyl isobutyl ketone): 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)
  • First Aid: (General first aid procedures); Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.; Skin: Water flush promptly - If this chemical contacts the skin, flush the contaminated skin with water promptly. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water promptly. If irritation persists after washing, get medical attention.; Breathing: Respiratory support; Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately. Source: The National Institute for Occupational Safety and Health (NIOSH)
  • 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]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H332: Harmful if inhaled [Warning Acute toxicity, inhalation]; H336: May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]; 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+P265, P271, P280, P303+P361+P353, P304+P340, P305+P351+P338, P317, P318, P319, P337+P317, 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% (2 of 4455) 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]; H319 (> 99.9%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H332 (97.1%): Harmful if inhaled [Warning Acute toxicity, inhalation]; H335 (93.7%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H336 (11.5%): May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]; H351 (11.8%): Suspected of causing cancer [Warning Carcinogenicity] Source: European Chemicals Agency (ECHA)
  • Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P261, P264+P265, P271, P280, P303+P361+P353, P304+P340, P305+P351+P338, P317, P318, P319, P337+P317, 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 4455 reports by companies from 80 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Reported as not meeting GHS hazard criteria per 2 of 4455 reports by companies.; There are 79 notifications provided by 4453 of 4455 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: H350: May cause cancer [Danger Carcinogenicity] Source: NITE-CMC
  • Precautionary Statement Codes: P203, P280, P318, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
  • GHS Hazard Statements: H225: Highly Flammable liquid and vapor [Danger Flammable liquids]; H320: Causes eye irritation [Warning 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]; H351: Suspected of causing cancer [Warning Carcinogenicity]; H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure] Source: NITE-CMC
  • NFPA Health Rating: 1 - Materials that, under emergency conditions, can cause significant irritation. 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: 0 - Materials that in themselves are normally stable, even under fire conditions. Source: Hazardous Substances Data Bank (HSDB)
  • Cosmetic Ingredient Review Conclusion: Based on the available animal and clinical data in this report, the CIR Expert Panel concludes that MIBK is safe as used in nail polish removers and as an alcohol denaturant in cosmetic products. Source: Cosmetic Ingredient Review (CIR)
  • Cosmetic Ingredient Review Finding(s): Safe for use in cosmetics, with qualifications Source: Cosmetic Ingredient Review (CIR)
  • Toxicity Summary: IDENTIFICATION AND USE: Methyl isobutyl ketone (MIBK) is a colorless liquid. It is used as a solvent for gums, resins, nitrocellulose, paints, varnishes, and lacquers. It is also used as denaturant for rubbing alcohol, in the manufacture of methyl amyl alcohol, and in dry-cleaning preparations. It is also widely used in rubber chemicals for the production of tyres. HUMAN STUDIES: Symptoms and signs of poisoning include: irritation of the eyes, skin, and respiratory tract, as well as CNS depression. Gastrointestinal pain and hepatic toxicity may occur with exposure to high concentrations. In workers exposed to up to 2050 mg MIBK/cu m (500 ppm) for 20-30 min per day and to 328 mg/cu m (80 ppm) for much of the remainder of the working day, over half of the 19 workers complained of weakness, loss of appetite, headache, eye irritation, stomach ache, nausea, vomiting, and sore throat. A few of the workers experienced insomnia, somnolence, heartburn, intestinal pain, and some unsteadiness. Four workers had slightly enlarged livers and six had a nonspecific colitis. Prolonged or repeated skin contact may cause drying and flaking of the skin. Accidental aspiration of liquid MIBK can cause c Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Bioconcentration: An estimated BCF of 3 was calculated in fish for methyl isobutyl ketone(SRC), using a log Kow of 1.31(1) and a regression-derived equation(2). According to a classification scheme(3), 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 70(SRC), determined from a log Kow of 1.31(2) and a regression-derived equation(3), indicates that methyl isobutyl ketone is expected to have high mobility in soil(SRC). Volatilization of methyl isobutyl ketone from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.4X10-4 atm-cu m/mole(SRC) derived from its vapor pressure, 19.9 mm Hg(4), and water solubility, 19,000 mg/L(5). Methyl isobutyl ketone is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). An 84% of theoretical BOD using activated sludge in the Japanese MITI test(6) suggests that biodegradation is an important environmental fate process in soil(SRC). Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Fate: AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 70(SRC), determined from a log Kow of 1.31(2) and a regression-derived equation(3), indicates that methyl isobutyl ketone is not 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 1.4X10-4 atm-cu m/mole(SRC), derived from its vapor pressure, 19.9 mm Hg(4), and water solubility, 19,000 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 9 hours and 6 days, respectively(SRC). According to a classification scheme(6), an estimated BCF of 3(SRC), from its log Kow(2) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). An 84% of theoretical BOD using activated sludge in the Japanese MITI test(8) suggests that biodegradation is an important environmental fate process in water(SRC). 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), methyl isobutyl ketone, which has a vapor pressure of 19.9 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase methyl isobutyl ketone 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 30(SRC), calculated from its rate constant of 1.3X10-11 cu cm/molecule-sec at 25 °C(3). Methyl isobutyl ketone absorbs UV at wavelengths >290 nm(3) and, therefore, may be susceptible to direct photolysis by sunlight(SRC). Source: Hazardous Substances Data Bank (HSDB)
  • Industry Uses: Sealant (barrier); Not Known or Reasonably Ascertainable; Intermediate; Surface modifier; Solvent; Other; Fuel Source: EPA Chemical Data Reporting (CDR)
  • Cosmetic Ingredient Review Link: CIR ingredient: MIBK Source: Cosmetic Ingredient Review (CIR)
  • Uses: Methyl isobutyl ketone is used as a solvent for gums, resins, paints, varnishes, lacquers, and nitrocellulose, as an alcohol denaturant, in the extraction of rare metals, and as a synthetic flavoring adjuvant. Source: EPA Hazardous Air Pollutants
  • Sources/Uses: Used as a solvent in the paint, synthetic resin, adhesive, aircraft, and pharmaceutical manufacturing industries; [ACGIH] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
  • Industrial Processes with risk of exposure: Textiles (Fiber & Fabric Manufacturing) [Category: Industry]; Painting (Solvents) [Category: Paint]; Working with Glues and Adhesives [Category: Other]; Plastic Composites Manufacturing [Category: Industry] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
  • Uses: Solvent for gums, resins, nitrocellulose, paints, varnishes, and lacquers. Denaturant for rubbing alcohol. In manufacture of methyl amyl alcohol. In dry-cleaning preparations. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: ... Extraction processes including extraction of uranium from fission products; organic synthesis ... . Source: Hazardous Substances Data Bank (HSDB)
  • Uses: ... Denaturant and solvent in cosmetic products. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: The major application of 4-methyl-2-pentanone is as a solvent for vinyl, epoxy, and acrylic resins, for natural resins, and for nitrocellulose. A further use is as a solvent for dyes in the printing industry. 4-Methyl-2-pentanone is also a versatile extracting agent, e.g., for the production of antibiotics, or the removal of paraffins from mineral oil for the production of lubricating oils. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: For more Uses (Complete) data for Methyl isobutyl ketone (9 total), please visit the HSDB record page. 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
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 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Record details

Chemical name

4-methylpentan-2-one; isobutyl methyl ketone (MIBK)

Chemical / IUPAC name

4-methylpentan-2-one; isobutyl methyl ketone (MIBK)

Regulatory information

Regulation

(EU) 2022/1531

See every entry this act set

CMR

CategoryCarcinogenicMutagenicReprotoxic
Cat. 2✓——

Key data

CAS
108-10-1
EC
203-550-1
Annex
II
Entry number
1689

Inventory links for 4-methylpentan-2-one; isobutyl methyl ketone (MIBK)

Inventory Shared CAS number
Ref 35359

MIBK

CAS: 108-10-1
EC: 203-550-1

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

Annex II 1686
Nearby record in the same annex

3-methylpyrazole

CAS: 1453-58-3
EC: 215-925-7
Annex II 1695
Nearby record in the same annex

Ammonium bromide

CAS: 12124-97-9
EC: 235-183-8

What Annex II means for 4-methylpentan-2-one; isobutyl methyl ketone (MIBK)

4-methylpentan-2-one; isobutyl methyl ketone (MIBK) 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.

This record is linked to 1 CosIng inventory ingredient for name and identifier cross-reference. 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. 4-methylpentan-2-one; isobutyl methyl ketone (MIBK) 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 108-10-1 is the unique numerical identifier assigned to 4-methylpentan-2-one; isobutyl methyl ketone (MIBK) 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.

4-methylpentan-2-one; isobutyl methyl ketone (MIBK) 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.
Open INCI Checker

Source note for Annex II record 4-methylpentan-2-one; isobutyl methyl ketone (MIBK)

This page summarizes one Annex II record for 4-methylpentan-2-one; isobutyl methyl ketone (MIBK) 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 4-methylpentan-2-one; isobutyl methyl ketone (MIBK), but confirm any final regulatory decision against the current official annex wording and source files.

View sourcesView updates

Tools & next steps

Check your formula

Paste a full INCI list to detect 4-methylpentan-2-one; isobutyl methyl ketone (MIBK) and other flagged EU annex records in one pass.

INCI Checker

Compare entries

Compare 4-methylpentan-2-one; isobutyl methyl ketone (MIBK) side by side with another annex record to review differences in restrictions, concentrations and annex placement.

Compare

Browse the annex

See all records in Annex II and compare regulatory conditions across substances in this annex.

Open Annex II