Substance profile
2-furaldehyde
2-furaldehyde is colorless, oily liquid Turns yellow to brown on exposure to air and light and resinifies with a peculiar odor, somewhat resembling the odor of benzaldehyde.
01 · Identification
What 2-furaldehyde is
2-furaldehyde is colorless, oily liquid Turns yellow to brown on exposure to air and light and resinifies with a peculiar odor, somewhat resembling the odor of benzaldehyde. Its molecular formula is C5H4O2 and its molecular weight is 96.08 g/mol. It boils at 162 °C, melts at -38.1 °C, is soluble in water.
Under the GHS it carries the signal word Danger. It is classed as flammable agents - 2nd degree.
02 · Identifiers
2-furaldehyde identifiers and molecular data
2-furaldehyde CAS number and EC number
2-furaldehyde molecular formula and molecular weight
03 · GHS classification
2-furaldehyde hazard classification
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
2-furaldehyde pictograms and signal word
2-furaldehyde hazard class and category
| Hazard class | Category | From code | Pictogram |
|---|---|---|---|
| Acute toxicity - oral GHS chapter 3.1 | Category 3 | H301 | GHS06 |
| Acute toxicity - dermal GHS chapter 3.1 | Category 4 | H312 | GHS07 |
| Acute toxicity - inhalation GHS chapter 3.1 | Category 3 | H331 | GHS06 |
| Skin corrosion/irritation GHS chapter 3.2 | Category 2 | H315 | GHS07 |
| Serious eye damage/eye irritation GHS chapter 3.3 | Category 2A | H319 | GHS07 |
| Carcinogenicity GHS chapter 3.6 | Category 2 | H351 | GHS08 |
| Specific target organ toxicity - single exposure GHS chapter 3.8 | Category 3 | H335 | GHS07 |
2-furaldehyde hazard statements (H-codes)
| Code | Hazard statement |
|---|---|
| H351 | Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H331 | Toxic if inhaled. |
| H301 | Toxic if swallowed. |
| H312 | Harmful in contact with skin. |
| H335 | May cause respiratory irritation. |
| H315 | Causes skin irritation. |
| H319 | Causes serious eye irritation. |
This page lists only the codes assigned to 2-furaldehyde. 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 2-furaldehyde
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 2-furaldehyde 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
2-furaldehyde precautionary statements
CLP Annex VI assigns 19 precautionary statements to 2-furaldehyde. 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
2-furaldehyde 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 | 2-фуралдехид |
| Spanish español | 2-Furaldehído |
| Czech čeština | 2-furaldehyd |
| Danish dansk | 2-furaldehyd |
| German Deutsch | 2-Furaldehyd Furfural2-Furylmethanal |
| Estonian eesti | 2-furaldehüüd |
| Greek ελληνικά | 2-φουραλδεΰδη |
| English English | 2-furaldehyde |
| French français | 2-furaldéhyde |
| Croatian hrvatski | 2-furaldehid |
| Italian italiano | 2-furaldeide furfurale |
| Latvian latviešu | 2-furaldehīds |
| Lithuanian lietuvių | 2-furaldehidas |
| Hungarian magyar | 2-furaldehid |
| Maltese Malti | 2-furaldeid |
| Dutch Nederlands | 2-furaldehyde |
| Polish polski | 2-furaldehyd |
| Portuguese português | 2-furaldeído |
| Romanian română | 2-furaldehidă |
| Slovak slovenčina | 2-furaldehyd |
| Slovenian slovenščina | 2-furaldehid |
| Finnish suomi | 2-furaldehydi |
| Swedish svenska | 2-furaldehyd |
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
2-furaldehyde GHS label elements
Everything CLP Annex VI fixes for 2-furaldehyde, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.
Danger
2-furaldehyde
- Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
- Toxic if inhaled.
- Toxic if swallowed.
- Harmful in contact with skin.
- May cause respiratory irritation.
- Causes skin irritation.
- Causes serious eye irritation.
- Obtain special instructions before use.
- 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.
- Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/…
- IF SWALLOWED:
- IF ON SKIN:
- IF INHALED:
- IF IN EYES:
- IF exposed or concerned:
- Immediately call a POISON CENTER/doctor/…
- Call a POISON CENTER/doctor/… if you feel unwell.
- Get medical advice/attention.
- Rinse mouth.
- If skin irritation occurs:
- If eye irritation persists:
- Remove contact lenses, if present and easy to do. Continue rinsing.
- Wash with plenty of water/…
Supplier name, address and telephone number· Product identifier·Nominal quantity
Need this as an actual label? Open 2-furaldehyde in the GHS label constructor →
07 · Health hazards
2-furaldehyde health hazards and exposure limits
2-furaldehyde carcinogenicity classification
Under the conditions of these 2-year gavage studies, there was some evidence of carcinogenic activity of furfural for male F344/N rats based on the occurrence of uncommon cholangiocarcinomas in two animals and bile duct dysplasia with fibrosis in two other animals. There was no evidence of carcinogenic activity for female F344/N rats that received doses of 0, 30,or 60 mg/kg furfural. There was clear evidence of carcinogenic activity for male B6C3F1 mice, based on increased incidences of hepatocellular adenomas and hepatocellular carcinomas. There was some evidence of carcinogenic activity in female B6C3F1 mice, based on increased incidences of hepatocellular adenomas. Renal cortical adenomas or carcinomas in male mice and squamous cell papillomas of the forestomach in female mice may have been related to exposure to furfural.
Source: US National Toxicology Program · TR-382: Toxicology and Carcinogenesis Studies of Furfural (CASRN 98-01-1) in F344/N Rats and B6C3F1 Mice (Gavage Studies) (1990 )
Evaluation: There is inadequate evidence in humans for the carcinogenicity of furfural. There is limited evidence in experimental animals for the carcinogenicity of furfural. Overall evaluation: Furfural is not classifiable as to its carcinogenicity to humans (Group 3).
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.
2-furaldehyde occupational exposure limits
| Limit | Value | Source |
|---|---|---|
| PEL | 5.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| PEL | 5 ppm (20 mg/m³) | Occupational Safety and Health Administration (OSHA) |
| PEL | TWA 5 ppm (20 mg/m3) [skin] See Appendix G | The National Institute for Occupational Safety and Health (NIOSH) |
| IDLH | 100 ppm (NIOSH, 2024) | CAMEO Chemicals |
| IDLH | 100.0 [ppm] | Haz-Map, Information on Hazardous Chemicals and Occupational Diseases |
| IDLH | 100 ppm | Hazardous Substances Data Bank (HSDB) |
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
2-furaldehyde 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.
2-furaldehyde boiling point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 161.7 °C (323.1 °F) | HSDB | |
| 161.67 °C (323 °F) | NIOSH | ||
| 161.72 °C (323.1 °F) | at 760 mmHg | CAMEO |
2-furaldehyde melting point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | -38.1 °C (-36.6 °F) | HSDB | |
| -36.67 °C (-34 °F) | NIOSH | ||
| -36.5 °C (-33.7 °F) | CAMEO |
2-furaldehyde density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Density | 1.16 g/cm³ | NIOSH | |
| 1.1594 g/cm³ | at 20 °C | HSDB | |
| 1.159 g/cm³ | at 20 °C | CAMEO |
2-furaldehyde solubility
| Property | Value | Conditions | Source |
|---|---|---|---|
| Solubility | Soluble in benzene, chloroform; very soluble in ethanol, acetone; miscible with ethyl ether | HSDB | |
| Soluble in alcohol, ether; 8.3% soluble in water at 20 °C | at 20 °C | HSDB | |
| In water, 7.41X10+4 mg/L at 25 °C | at 25 °C | HSDB |
2-furaldehyde vapor pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor pressure | 2 mmHg | NIOSH | |
| 1 mmHg | at 20 °C | CAMEO | |
| 1.1251 mmHg | at 20 °C | ICSC |
2-furaldehyde flash point
| Property | Value | Conditions | Source |
|---|---|---|---|
| Flash point | 60 °C (140 °F) | HSDB |
2-furaldehyde autoignition temperature
| Property | Value | Conditions | Source |
|---|---|---|---|
| Autoignition temperature | 316 °C (600.8 °F) | HSDB | |
| 392.78 °C (739 °F) | CAMEO | ||
| 315 °C (599 °F) | ICSC |
2-furaldehyde lower explosive limit (LEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Lower explosive limit (LEL) | 2.1 % by volume | HSDB |
2-furaldehyde upper explosive limit (UEL)
| Property | Value | Conditions | Source |
|---|---|---|---|
| Upper explosive limit (UEL) | 19.3 % by volume | HSDB |
2-furaldehyde vapor density
| Property | Value | Conditions | Source |
|---|---|---|---|
| Vapor density | 3.3 (air = 1) | HSDB | |
| 3.31 (air = 1) | CAMEO |
2-furaldehyde odor threshold
| Property | Value | Conditions | Source |
|---|---|---|---|
| Odor threshold | Detection in water: 3.00X10+3 ppb (gas chromatically pure) | HSDB | |
| 0.0240 mg/cu m (odor low) 20.0 mg/cu m (odor high) | HSDB | ||
| Recognition/human odor perception: 1.0 mg/cu m | HSDB |
2-furaldehyde critical temperature and pressure
| Property | Value | Conditions | Source |
|---|---|---|---|
| Critical temperature and pressure | 396.85 °C (746.3 °F) | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
09 · Fire and explosion
2-furaldehyde 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.
2-furaldehyde fire potential
Flammability of furfural is comparable to that of kerosene or No 1 fuel oil.
Source: Hazardous Substances Data Bank (HSDB)
10 · Handling and storage
2-furaldehyde storage and handling
2-furaldehyde peroxide formation
D*: Other compounds that may form peroxides
Source: Lab and Research Safety, University of Minnesota
2-furaldehyde safe storage
Separated from strong bases, strong acids, strong oxidants and food and feedstuffs. Keep in the dark. Well closed. Ventilation along the floor. Store in an area without drain or sewer access.
Source: ILO-WHO International Chemical Safety Cards (ICSCs)
2-furaldehyde storage conditions
Keep in air tight container and protect from light
Source: Hazardous Substances Data Bank (HSDB)
2-furaldehyde incompatible materials
...Can react with oxidizing materials.
Source: Hazardous Substances Data Bank (HSDB)
2-furaldehyde reactivity
FURFURAL reacts with sodium hydrogen carbonate. It also can react with strong oxidizers. An exothermic resinification of almost explosive violence can occur upon contact with strong mineral acids or alkalis. It forms condensation products with many types of compounds, including phenol, amines and urea. (NTP, 1992).
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check 2-furaldehyde in the storage compatibility matrix →
11 · Questions
2-furaldehyde — frequently asked questions
What is the CAS number of 2-furaldehyde?
The CAS number of 2-furaldehyde is 98-01-1. Its EC number is 202-627-7.
What is the chemical formula of 2-furaldehyde?
The molecular formula of 2-furaldehyde is C5H4O2 and its molecular weight is 96.08 g/mol.
What does a 2-furaldehyde label have to show?
Under CLP Annex VI the label for 2-furaldehyde carries the pictograms Skull and crossbones and Health hazard and the signal word is Danger.
Is 2-furaldehyde flammable?
CLP Annex VI assigns 2-furaldehyde no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it. The flash point reported for it is 60 °C (140 °F) (HSDB).
Is 2-furaldehyde a carcinogen?
CLP Annex VI assigns 2-furaldehyde H351 — suspected of causing cancer. That is category 2: the evidence points that way but is not conclusive. IARC places it in Group 3: not classifiable as to its carcinogenicity to humans.
What is the exposure limit for 2-furaldehyde?
The US occupational exposure limit reported for 2-furaldehyde is 5.0 [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 2-furaldehyde?
The boiling point reported for 2-furaldehyde is 161.7 °C (323.1 °F) (HSDB).
What is the melting point of 2-furaldehyde?
The melting point reported for 2-furaldehyde is -38.1 °C (-36.6 °F) (HSDB).
How should 2-furaldehyde be stored?
Keep in air tight container and protect from light (Hazardous Substances Data Bank (HSDB))
Nearby
Substances next to 2-furaldehyde
Keep going: substances starting with 0–9, or search the whole database by name, CAS number, pictogram or signal word.