Substance profile
Furan
Furan is a colorless liquid, turns brown upon standing with an ethereal odor.
01 · Identification
What Furan is
Furan is a colorless liquid, turns brown upon standing with an ethereal odor. Its molecular formula is C4H4O and its molecular weight is 68.07 g/mol. It boils at 31.5 °C, melts at -85.6 °C, is soluble in water.
Under the GHS it carries the signal word Danger. It is classed as carcinogens.
02 · Identifiers
Furan identifiers and molecular data
Furan CAS number and EC number
Furan molecular formula and molecular weight
03 · GHS classification
Furan hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
Furan pictograms and signal word
Furan hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Flammable liquids GHS chapter 2.6 | Category 1 | H224 | GHS02 |
| Acute toxicity - oral GHS chapter 3.1 | Category 4 | H302 | GHS07 |
| Acute toxicity - inhalation GHS chapter 3.1 | Category 4 | H332 | GHS07 |
| Skin corrosion/irritation GHS chapter 3.2 | Category 2 | H315 | GHS07 |
| Germ cell mutagenicity GHS chapter 3.5 | Category 2 | H341 | GHS08 |
| Carcinogenicity GHS chapter 3.6 | Category 1A or 1B | H350 | GHS08 |
| Specific target organ toxicity - repeated exposure GHS chapter 3.9 | Category 2 | H373 | GHS08 |
| Hazardous to the aquatic environment - chronic GHS chapter 4.1 | Category 3 | H412 | — |
Where two values are shown with “or”, the hazard statement is shared by more than one category or by more than one class, and the code alone does not say which. H272, for example, belongs to oxidising liquids and to oxidising solids — the physical state decides. The binding answer for a specific entry is in the CLP Annex VI table itself.
Furan hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H224 | Extremely flammable liquid and vapour. |
| H350 | May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H341 | Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H332 | Harmful if inhaled. |
| H302 | Harmful if swallowed. |
| H373 | May cause 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>. |
| H315 | Causes skin irritation. |
| H412 | Harmful to aquatic life with long lasting effects. |
Furan supplemental EU statements (EUH)
| Code | Statement |
|---|---|
| EUH019 | May form explosive peroxides. |
This page lists only the codes assigned to Furan. 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 Furan
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 Furan 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
Furan precautionary statements
CLP Annex VI assigns 23 precautionary statements to Furan. 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.
Disposal
What has to happen to the contents and the empty container.
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
Furan 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 | фуран |
| Spanish español | Furano |
| Czech čeština | furan |
| Danish dansk | furan |
| German Deutsch | Furan |
| Estonian eesti | furaan |
| Greek ελληνικά | φουράνιο |
| English English | furan |
| French français | furane |
| Croatian hrvatski | furan |
| Italian italiano | furano |
| Latvian latviešu | furāns |
| Lithuanian lietuvių | furanas |
| Hungarian magyar | furán |
| Maltese Malti | furan |
| Dutch Nederlands | furan |
| Polish polski | furan |
| Portuguese português | furano |
| Romanian română | furan |
| Slovak slovenčina | furán |
| Slovenian slovenščina | furan |
| Finnish suomi | furaani |
| Swedish svenska | furan |
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
Furan GHS label elements
Everything CLP Annex VI fixes for Furan, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
Furan
- Extremely flammable liquid and vapour.
- May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Harmful if inhaled.
- Harmful if swallowed.
- May cause 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>.
- Causes skin irritation.
- Harmful to aquatic life with long lasting effects.
- May form explosive peroxides.
- Obtain special instructions before use.
- 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.
- Wash … thoroughly after handling.
- Do not eat, drink or smoke when using this product.
- Use only outdoors or in a well-ventilated area.
- Avoid release to the environment.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF ON SKIN:
- IF INHALED:
- IF exposed or concerned:
- Call a POISON CENTER/doctor/… if you feel unwell.
- Get medical advice/attention.
- Get medical advice/attention if you feel unwell.
- Rinse mouth.
- If skin irritation occurs:
- Wash with plenty of water/…
- Store in a well-ventilated place.
- Dispose of contents/container to …
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open Furan in the GHS label constructor →
07 · Health hazards
Furan health hazards and exposure limits
Furan hazard summary
Inhalation can cause anesthesia; Absorbed through skin; [Merck Index] May cause liver damage; Corrosive to the mouth and GI tract in toxicology studies; [HSDB] Causes narcosis; Contact can irritate or burn skin and eyes; [CHRIS] Furan is a skin irritant. [Quick CPC] A respiratory tract irritant; Inhalation of vapor can cause pulmonary edema; [ICSC] Doses as low as 2 mg/kg can cause severe injury to the liver and kidneys. Causes liver tumors in high-dose animal studies; No data on human use; Worker exposure by all routes should be minimized to the fullest extent possible. [AIHA]
Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Furan carcinogenicity classification
Under the conditions of these 2-year gavage studies there was clear evidence of carcinogenic activity of furan in male and female F344/N rats based on increased incidences of cholangiocarcinoma and hepatocellular neoplasms of the liver and on increased incidences of mononuclear cell leukemia. There was clear evidence of carcinogenic activity of furan in male and female B6C3F1 mice based on increased incidences of hepatocellular neoplasms of the liver and benign pheochromocytomas of the adrenal gland.
Source: US National Toxicology Program · TR-402: Toxicology and Carcinogenesis Studies of Furan (CASRN 110-00-9) in F344 Rats and B6C3F1 Mice (Gavage Studies) (1993 )
Evaluation: There is inadequate evidence in humans for the carcinogenicity of furan. There is sufficient evidence in experimental animals for the carcinogenicity of furan. Overall evaluation: Furan is possibly carcinogenic to humans (Group 2B).
Source: Hazardous Substances Data Bank (HSDB)
Furan: reasonably anticipated to be a human carcinogen.
Source: Hazardous Substances Data Bank (HSDB)
An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.
Furan occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| IDLH | 13 ppm [From IDLH Table: Furan] (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 13.0 [ppm] | 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
Furan 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.
Furan boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 31.5 °C (88.7 °F) | HSDB | |
| 32.22 °C (90 °F) | at 758 mmHg | CAMEO | |
| 31.3 °C (88.3 °F) | ICSC |
Furan melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -85.61 °C (-122.1 °F) | HSDB | |
| -86.11 °C (-123 °F) | CAMEO | ||
| -85.6 °C (-122.1 °F) | ICSC |
Furan density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 0.9514 g/cm³ | at 20 °C | HSDB |
| 0.9731 g/cm³ | at 19.4 °C | HSDB | |
| 0.9371 g/cm³ | at 19.4 °C | CAMEO |
Furan solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Soluble in alcohol and ether | HSDB | |
| Slightly soluble in chloroform; very soluble in ethanol, ether; soluble in acetone, benzene | HSDB | ||
| In water, 1X10+4 mg/L at 25 °C | at 25 °C | HSDB |
Furan vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 493 mmHg | at 20 °C | CAMEO |
| 493.541 mmHg | at 20 °C | ICSC | |
| 600 mmHg | at 25 °C, from experimentally derived coefficients | HSDB |
Furan flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | -35.56 °C (-32 °F) | HSDB | |
| -35 °C (-31 °F) | ICSC | ||
| Less than 32F (EPA, 1998) | CAMEO |
Furan autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 390 °C (734 °F) | ICSC |
Furan lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 2.3 % by volume | % by vol | HSDB |
| 2.3 % by volume | CAMEO |
Furan upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 14.3 % by volume | % by vol | HSDB |
| 14.3 % by volume | CAMEO |
Furan vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 2.3 (air = 1) | HSDB |
Furan critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 214 °C (417.2 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
Furan 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.
Furan fire potential
A very dangerous fire hazard when exposed to heat or flame.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
Furan storage and handling
Furan peroxide formation
B*: Compounds that form peroxides on concentration (distillation/evaporation)
Source: Lab and Research Safety, University of Minnesota
Furan safe storage
Fireproof. Well closed. Cool. Keep in the dark. Store only if stabilized. Separated from strong oxidants and acids. Provision to contain effluent from fire extinguishing. Store in an area without drain or sewer access.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Furan storage conditions
Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in an explosion-proof refrigerator. Keep in a tightly closed container under an inert atmosphere and protect from light for long-term storage. A regulated, marked area should be established where this chemical is handled, used, or stored ...
Source: Hazardous Substances Data Bank (HSDB)
Furan incompatible materials
Violent reaction with acids, oxidizers. Unless stablized with an inhibitor, air exposure forms unstable peroxides.
Source: Hazardous Substances Data Bank (HSDB)
Furan reactivity
FURAN is sensitive to heat and may turn brown upon standing. This compound may be light sensitive. When uninhibited, this compound forms explosive peroxides on exposure to air. This chemical may react with oxidizers, acids, peroxides and oxygen. It resinifies on evaporation or when in contact with mineral acids, but it is stable in alkalis. (NTP, 1992).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Furan in the storage compatibility matrix →
11 · Transport
Furan 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.
Furan under UN 2389 — shipping name, class and packing group
Europe · ADR 2025, Table A
| Proper shipping name (3.1.2) | Class | Classification code | PG | Labels (column 5) |
|---|---|---|---|---|
| FURAN | 3 | F1 | I | |
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) |
|---|---|---|---|
| Furan | 3 | I | |
Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 3 is “Flammable and combustible liquid” (49 CFR 173.2).
12 · Questions
Furan — frequently asked questions
What is the CAS number of Furan?
The CAS number of Furan is 110-00-9. Its EC number is 203-727-3.
What is the chemical formula of Furan?
The molecular formula of Furan is C4H4O and its molecular weight is 68.07 g/mol.
What does a Furan label have to show?
Under CLP Annex VI the label for Furan carries the pictograms Flame, Health hazard and Exclamation mark and the signal word is Danger.
Is Furan flammable?
Yes. CLP Annex VI assigns Furan H224 — extremely flammable liquid and vapour. The flash point reported for it is -35.56 °C (-32 °F) (HSDB).
Is Furan a carcinogen?
Yes. CLP Annex VI classifies Furan as a category 1A or 1B carcinogen and assigns it H350: may cause cancer. IARC places it in Group 2B: possibly carcinogenic to humans.
What is the boiling point of Furan?
The boiling point reported for Furan is 31.5 °C (88.7 °F) (HSDB).
What is the melting point of Furan?
The melting point reported for Furan is -85.61 °C (-122.1 °F) (HSDB).
How should Furan be stored?
CLP Annex VI assigns Furan the storage statement P403. Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in an explosion-proof refrigerator. Keep in a tightly closed container under an inert atmosphere and protect from light for long-term storage. A regulated, marked area should be established where this chemical is handled, used, or stored ... (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to Furan
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