Substance profile
Hexan-2-one
Hexan-2-one is a colorless liquid with a characteristic acetone like odor, but more pungent.
01 · Identification
What Hexan-2-one is
Hexan-2-one is a colorless liquid with a characteristic acetone like odor, but more pungent. Its molecular formula is C6H12O and its molecular weight is 100.16 g/mol. It boils at 127 °C, melts at -55.5 °C.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 3rd degree.
02 · Identifiers
Hexan-2-one identifiers and molecular data
Hexan-2-one CAS number and EC number
Hexan-2-one molecular formula and molecular weight
Other names for Hexan-2-one
- methyl butyl ketone
- butyl methyl ketone
- methyl-n-butyl ketone
03 · GHS classification
Hexan-2-one hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Hexan-2-one pictograms and signal word
Hexan-2-one hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable liquids GHS chapter 2.6 | Category 3 | H226 | GHS02 |
| Specific target organ toxicity - single exposure GHS chapter 3.8 | Category 3 narcotic | H336 | GHS07 |
| Specific target organ toxicity - repeated exposure GHS chapter 3.9 | Category 1 | H372 | GHS08 |
Hexan-2-one hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H226 | Flammable liquid and vapour. |
| H361f | Suspected of damaging fertility. |
| H336 | May cause drowsiness or dizziness. |
| H372 | Causes damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
This page lists only the codes assigned to Hexan-2-one. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
Safety Data Sheet
Getting an SDS for Hexan-2-one
A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Hexan-2-one issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.
04 · Precautionary statements
Hexan-2-one precautionary statements
CLP Annex VI assigns 8 precautionary statements to Hexan-2-one. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.
Prevention
What to do before and during handling so the hazard never happens.
Response
What to do once exposure, spillage or fire has already happened.
Reading the notation. … is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.
05 · Names in the regulation
Hexan-2-one name in 23 EU languages
CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.
| Language | Name in CLP Annex VI Part 3 |
|---|---|
| Bulgarian български | хексан-2-он бутилметилкетонn -бутилметилкетон |
| Spanish español | Hexan-2-ona metilbutilcetonabutilmetilcetonametil- n -butil-cetona |
| Czech čeština | hexan-2-on methyl(butyl)ketonbutyl(methyl)ketonmethyl- n -butyl-keton |
| Danish dansk | hexan-2-on methylbutylketonbutylmethylketonmethyl- n -butylketon |
| German Deutsch | 2-Hexanon MethylbutylketonButylmethylketonMethyl- n -butylketon |
| Estonian eesti | heksaan-2-oon metüülbutüülketoonbutüülmetüülketoonmetüül- n -butüülketoon |
| Greek ελληνικά | εξαν-2-όνη μεθυλοβουτυλοκετόνηβουτυλομεθυλοκετόνημεθυλο- n -βουτυλοκετόνη |
| English English | hexan-2-one methyl butyl ketonebutyl methyl ketonemethyl- n -butyl ketone |
| French français | hexan-2-one méthylbutylcétonebutylméthylcétoneméthyl- n -butylcétone |
| Croatian hrvatski | heksan-2-on metil-butil-ketonbutil-metil-ketonmetil- n -butil-keton |
| Italian italiano | 2-esanone metil butil chetonemetil-n-butil chetone |
| Latvian latviešu | heksān-2-ons metilbutilketonsbutilmetilketonsmetil- n -butilketons |
| Lithuanian lietuvių | heksan-2-onas metilbutilketonasbutilmetilketonasmetil- n -butilketonas |
| Hungarian magyar | hexán-2-on metil-butil-ketonbutil-metil-ketonmetil- n -butil-keton |
| Maltese Malti | essan-2-on keton tal-butil tal-metilketon tal-metil tal-butilketon tal-metil- n -butil |
| Dutch Nederlands | hexaan-2-on methylbutylketonbutylmethylketonmethyl- n -butylketon |
| Polish polski | heksan-2-on metylobutyloketonketon butylowo-metylowyketon metylo- n -butylowy |
| Portuguese português | hexan-2-ona metilbutilcetonabutilmetilcetonametil- n- butilcetona |
| Romanian română | hexan-2-onă metil-butil-cetonăbutil-metil-cetonămetil- n -butil-cetonă |
| Slovak slovenčina | hexán-2-ón butyl(metyl)ketón |
| Slovenian slovenščina | heksan-2-on metil butil ketonbutil metil ketonmetil- n -butil keton |
| Finnish suomi | heksan-2-oni metyylibutyyliketonibutyylimetyyliketonimetyyli- n -butyyliketoni |
| Swedish svenska | hexan-2-on metylbutylketonbutylmetylketonmetyl- n -butylketon |
All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.
06 · Label elements
Hexan-2-one GHS label elements
Everything CLP Annex VI fixes for Hexan-2-one, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Hexan-2-one
- Flammable liquid and vapour.
- Suspected of damaging fertility.
- May cause drowsiness or dizziness.
- Causes damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
- Keep container tightly closed.
- Use explosion-proof [electrical/ventilating/lighting/…] equipment.
- Use only non-sparking tools.
- Do not breathe dust/fume/gas/mist/vapours/spray.
- Do not eat, drink or smoke when using this product.
- Get medical advice/attention if you feel unwell.
- Store in a well-ventilated place.
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Hexan-2-one in the GHS label constructor →
07 · Health hazards
Hexan-2-one health hazards and exposure limits
Hexan-2-one hazard summary
2-Hexanone is also known as methyl n-butyl ketone, MBK, or propyl acetone. It is a clear, colorless liquid with a sharp odor. It dissolves very easily in water, and can evaporate easily into the air as a vapor. It was used in the past in paint and paint thinner, to make other chemical substances, and to dissolve oils and waxes. It is no longer made or used in the United States because it has harmful health effects. It is formed as a waste product resulting from industrial activities such as making wood pulp and producing gas from coal, and in oil shale operations.
Source: Agency for Toxic Substances and Disease Registry (ATSDR)
Hexan-2-one occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 100.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| PEL | 100 ppm (410 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| PEL | TWA 100 ppm (410 mg/m3) See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| REL | 1 ppm (4 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| REL | TWA 1 ppm (4 mg/m3) | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 1600 ppm (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 1600.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | Excerpts from Documentation for IDLHs: Volunteers exposed to 1,000 ppm reported a strong odor and transient, moderate eye and nasal irritation [DiVencenzo et al. 1978]. | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.
08 · Physical and chemical properties
Hexan-2-one properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
Hexan-2-one boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 127.2 °C (261 °F) | HSDB | |
| 127.78 °C (262 °F) | NIOSH | ||
| 127.22 °C (261 °F) | at 760 mmHg | CAMEO |
Hexan-2-one melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -55.5 °C (-67.9 °F) | HSDB | |
| -57.22 °C (-71 °F) | NIOSH |
Hexan-2-one density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.81 g/cm³ | NIOSH | |
| 0.83 g/cm³ | at 20 °C | HSDB | |
| 0.812 g/cm³ | at 20 °C | CAMEO |
Hexan-2-one solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Sol in acetone; miscible in ethanol and ether | HSDB | |
| 1.4 wt% in water at 20 °C | at 20 °C | HSDB | |
| In water, 1.72X10+4 mg/L at 20 °C | at 20 °C | HSDB |
Hexan-2-one vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 11 mmHg | NIOSH | |
| 2 mmHg | at 20 °C | CAMEO | |
| 11.6 mmHg | at 25 °C | HSDB |
Hexan-2-one flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 25 °C (77 °F) | closed cup | HSDB |
| 35 °C (95 °F) | HSDB | ||
| 25 °C (77 °F) | Closed cup | HSDB |
Hexan-2-one autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 423.89 °C (795 °F) | HSDB | |
| 423 °C (793.4 °F) | ICSC |
Hexan-2-one lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 1.2 % by volume | HSDB |
Hexan-2-one upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 8 % by volume | HSDB |
Hexan-2-one vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3.5 (air = 1) | HSDB | |
| 3.45 (air = 1) | CAMEO |
Hexan-2-one odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | ODOR 3 PPM: 3= EASILY NOTICEABLE; IRRITATION 2 PPM: 2= FAINT. | HSDB | |
| 0.28-0.35 mg/cu m | HSDB | ||
| In air is 0.076 ppm and in water is 0.25 mg/L. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Hexan-2-one fire and explosion behaviour
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Hexan-2-one fire potential
Dangerous fire and explosion hazard when exposed to heat or flame ...
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Hexan-2-one storage and handling
Hexan-2-one safe storage
Fireproof. Separated from strong oxidants.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Hexan-2-one storage conditions
MATERIALS WHICH ARE TOXIC AS STORED OR WHICH CAN DECOMPOSE INTO TOXIC COMPONENTS ... SHOULD BE STORED IN A COOL WELL VENTILATED PLACE, OUT OF THE DIRECT RAYS OF THE SUN, AWAY FROM AREAS OF HIGH FIRE HAZARD, AND SHOULD BE PERIODICALLY INSPECTED. INCOMPATIBLE MATERIALS SHOULD BE ISOLATED ...
Source: Hazardous Substances Data Bank (HSDB)
Hexan-2-one incompatible materials
Strong oxidizers.
Source: Hazardous Substances Data Bank (HSDB)
Hexan-2-one reactivity
METHYL BUTYL KETONE is incompatible with oxidizing agents. It may also react with strong bases and reducing agents. (NTP, 1992)
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Hexan-2-one in the storage compatibility matrix →
11 · Questions
Hexan-2-one — frequently asked questions
What is the CAS number of Hexan-2-one?
The CAS number of Hexan-2-one is 591-78-6. Its EC number is 209-731-1.
What is the chemical formula of Hexan-2-one?
The molecular formula of Hexan-2-one is C6H12O and its molecular weight is 100.16 g/mol.
What does a Hexan-2-one label have to show?
Under CLP Annex VI the label for Hexan-2-one carries the pictograms Flame, Health hazard and Exclamation mark and the signal word is Danger.
Is Hexan-2-one flammable?
Yes. CLP Annex VI assigns Hexan-2-one H226 — flammable liquid and vapour. The flash point reported for it is 25 °C (77 °F), closed cup (HSDB).
Is Hexan-2-one a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Hexan-2-one. Annex VI is a list of agreed classifications, not a list of substances found safe, so this is an absence of a classification rather than a clean bill of health.
What is the exposure limit for Hexan-2-one?
The US occupational exposure limit reported for Hexan-2-one is 100.0 [ppm] (Haz-Map, Information on Hazardous Chemicals and Occupational Diseases). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.
What is the boiling point of Hexan-2-one?
The boiling point reported for Hexan-2-one is 127.2 °C (261 °F) (HSDB).
What is the melting point of Hexan-2-one?
The melting point reported for Hexan-2-one is -55.5 °C (-67.9 °F) (HSDB).
How should Hexan-2-one be stored?
CLP Annex VI assigns Hexan-2-one the storage statement P403. MATERIALS WHICH ARE TOXIC AS STORED OR WHICH CAN DECOMPOSE INTO TOXIC COMPONENTS ... SHOULD BE STORED IN A COOL WELL VENTILATED PLACE, OUT OF THE DIRECT RAYS OF THE SUN, AWAY FROM AREAS OF HIGH FIRE HAZARD, AND SHOULD BE PERIODICALLY INSPECTED. INCOMPATIBLE MATERIALS SHOULD BE ISOLATED ... (Hazardous Substances Data Bank (HSDB))
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