Substance profile
Pentane-2,4-dione
Pentane-2,4-dione is a colorless or slightly yellow liquid with a pleasant odor.
01 · Identification
What Pentane-2,4-dione is
Pentane-2,4-dione is a colorless or slightly yellow liquid with a pleasant odor. Its molecular formula is C5H8O2 and its molecular weight is 100.12 g/mol. It boils at 138 °C, melts at -23 °C.
Under the GHS it carries the signal word Warning. It is classed as flammable agents - 3rd degree.
02 · Identifiers
Pentane-2,4-dione identifiers and molecular data
Pentane-2,4-dione CAS number and EC number
Pentane-2,4-dione molecular formula and molecular weight
Other names for Pentane-2,4-dione
- acetylacetone
03 · GHS classification
Pentane-2,4-dione hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Pentane-2,4-dione pictograms and signal word
Pentane-2,4-dione hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable liquids GHS chapter 2.6 | Category 3 | H226 | GHS02 |
| Acute toxicity - oral GHS chapter 3.1 | Category 4 | H302 | GHS07 |
Pentane-2,4-dione hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H226 | Flammable liquid and vapour. |
| H302 | Harmful if swallowed. |
This page lists only the codes assigned to Pentane-2,4-dione. 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 Pentane-2,4-dione
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 Pentane-2,4-dione 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
Pentane-2,4-dione precautionary statements
CLP Annex VI assigns 9 precautionary statements to Pentane-2,4-dione. 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
Pentane-2,4-dione 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 | пентан-2,4-дион ацетилацетон |
| Spanish español | Pentano-2,4-diona acetilacetona |
| Czech čeština | pentan-2,4-dion acetylaceton |
| Danish dansk | 2,4-pentandion acetylacetone |
| German Deutsch | 2,4-Pentandion Acetylaceton |
| Estonian eesti | pentaan-2,4-dioon atsetüülatsetoon |
| Greek ελληνικά | πεντανο-2,4-διόνη ακετυλακετόνη |
| English English | pentane-2,4-dione acetylacetone |
| French français | pentane-2,4-dione acétylacétone |
| Croatian hrvatski | pentan-2,4-dion acetil-aceton |
| Italian italiano | 2,4-pentandione acetilacetone |
| Latvian latviešu | pentān-2,4-dions acetilacetons |
| Lithuanian lietuvių | 2,4-pentandionas acetilacetonas |
| Hungarian magyar | pentán-2,4-dion acetilaceton |
| Maltese Malti | pentan-2,4-dion aċetilaċetun |
| Dutch Nederlands | pentaan-2,4-dion acetylaceton |
| Polish polski | pentano-2,4-dion acetyloaceton |
| Portuguese português | pentano-2,4-diona acetilacetona |
| Romanian română | pentan-2,4-dionă acetilacetonă |
| Slovak slovenčina | pentán-2,4-dión acetylacetón |
| Slovenian slovenščina | pentan-2,4-dion acetilaceton |
| Finnish suomi | 2,4-pentaanidioni asetyyliasetoni |
| Swedish svenska | pentan-2,4-dion acetylaceton |
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
Pentane-2,4-dione GHS label elements
Everything CLP Annex VI fixes for Pentane-2,4-dione, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Warning
Pentane-2,4-dione
- Flammable liquid and vapour.
- Harmful if swallowed.
- 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 eat, drink or smoke when using this product.
- IF SWALLOWED:
- Call a POISON CENTER/doctor/… if you feel unwell.
- Rinse mouth.
- Store in a well-ventilated place.
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Pentane-2,4-dione in the GHS label constructor →
07 · Physical and chemical properties
Pentane-2,4-dione 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.
Pentane-2,4-dione boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 138 °C (280.4 °F) | HSDB | |
| 140.39 °C (284.7 °F) | at 760 mmHg | CAMEO | |
| 140 °C (284 °F) | ICSC |
Pentane-2,4-dione melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -23 °C (-9.4 °F) | HSDB | |
| -23.5 °C (-10.3 °F) | CAMEO |
Pentane-2,4-dione density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.9706 g/cm³ | HSDB | |
| 0.975 g/cm³ | at 20 °C | CAMEO | |
| 0.9721 g/cm³ | at 25 °C | HSDB |
Pentane-2,4-dione solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | One part dissolves in about 8 parts water | HSDB | |
| Fairly soluble in neutral water | HSDB | ||
| In water, 166,000 mg/L at 20 °C | at 20 °C | HSDB |
Pentane-2,4-dione vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 6.9756 mmHg | at 20 °C | ICSC |
| 2.96 mmHg | Haz-Map |
Pentane-2,4-dione flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 38 °C (100.4 °F) | HSDB | |
| 40.56 °C (105 °F) | HSDB | ||
| 33.89 °C (93 °F) | HSDB |
Pentane-2,4-dione autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 340 °C (644 °F) | HSDB |
Pentane-2,4-dione lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 2.4 % by volume | CAMEO |
Pentane-2,4-dione upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 11.6 % by volume | CAMEO |
Pentane-2,4-dione vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3.5 (air = 1) | HSDB | |
| 3.45 (air = 1) | ICSC |
Pentane-2,4-dione odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | 0.010 ppm | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
08 · Fire and explosion
Pentane-2,4-dione 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.
Pentane-2,4-dione fire potential
Flammable liquid when exposed to heat or flame.
Source: Hazardous Substances Data Bank (HSDB)
09 · Handling and storage
Pentane-2,4-dione storage and handling
Pentane-2,4-dione safe storage
Fireproof. Separated from strong oxidants. Keep in the dark.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Pentane-2,4-dione storage conditions
Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Storage class (TRGS 510): 3: Flammable liquids.
Source: Hazardous Substances Data Bank (HSDB)
Pentane-2,4-dione incompatible materials
Incompatible materials: Strong oxidizing agents, reducing agents, strong bases, metals.
Source: Hazardous Substances Data Bank (HSDB)
Pentane-2,4-dione reactivity
Ketones, such as PENTANE-2,4-DIONE, are reactive with many acids and bases liberating heat and flammable gases (e.g., H2). The amount of heat may be sufficient to start a fire in the unreacted portion of the ketone. Ketones react with reducing agents such as hydrides, alkali metals, and nitrides to produce flammable gas (H2) and heat. Ketones are incompatible with isocyanates, aldehydes, cyanides, peroxides, and anhydrides. They react violently with aldehydes, HNO3, HNO3 + H2O2, and HClO4. May dissolve plastics (USCG, 1999).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Pentane-2,4-dione in the storage compatibility matrix →
10 · Transport
Pentane-2,4-dione UN number and transport classification
Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.
Pentane-2,4-dione under UN 2310 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| PENTANE-2,4-DIONE | 3 | FT1 | III | |
Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 3 is “Flammable liquids” (ADR 2.1.1.1).
United States · 49 CFR 172.101 Hazardous Materials Table
| Proper shipping name (column 2) | Class or division | PG | Labels (column 6) |
|---|---|---|---|
| Pentane-2,4-dione | 3 | III | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 3 is “Flammable and combustible liquid” (49 CFR 173.2).
11 · Questions
Pentane-2,4-dione — frequently asked questions
What is the CAS number of Pentane-2,4-dione?
The CAS number of Pentane-2,4-dione is 123-54-6. Its EC number is 204-634-0.
What is the chemical formula of Pentane-2,4-dione?
The molecular formula of Pentane-2,4-dione is C5H8O2 and its molecular weight is 100.12 g/mol.
What does a Pentane-2,4-dione label have to show?
Under CLP Annex VI the label for Pentane-2,4-dione carries the pictograms Flame and Exclamation mark and the signal word is Warning.
Is Pentane-2,4-dione flammable?
Yes. CLP Annex VI assigns Pentane-2,4-dione H226 — flammable liquid and vapour. The flash point reported for it is 38 °C (100.4 °F) (HSDB).
Is Pentane-2,4-dione a carcinogen?
CLP Annex VI records no harmonised carcinogenicity classification for Pentane-2,4-dione. 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 boiling point of Pentane-2,4-dione?
The boiling point reported for Pentane-2,4-dione is 138 °C (280.4 °F) (HSDB).
What is the melting point of Pentane-2,4-dione?
The melting point reported for Pentane-2,4-dione is -23 °C (-9.4 °F) (HSDB).
How should Pentane-2,4-dione be stored?
CLP Annex VI assigns Pentane-2,4-dione the storage statement P403. Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Storage class (TRGS 510): 3: Flammable liquids. (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Pentane-2,4-dione
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