What is CAS 110-00-9 for Furan?

CAS 110-00-9 is the unique numerical identifier assigned to Furan by the Chemical Abstracts Service. It is used to cross-reference the substance across regulatory databases, raw material specifications and safety assessment reports.

Annex II Entry 732 CMR15/10/2010

Furan

Q: Is Furan banned in EU cosmetics?

Yes. Furan 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.

Q: What does the CMR classification mean for Furan?

Furan 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 only be used if assessed safe by the SCCS.

Q: How do I check if my product formula contains Furan?

Use the INCI Checker tool on CosIng Checker to paste your full ingredient list and scan it against all Annex II–VI entries. The tool highlights any ingredients that match restricted, prohibited or allergen-flagged records.

Furan is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.

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Prohibited substance— Annex II, EU Regulation 1223/2009

Entry: 732

CMR

Chemical identity and properties

PubChem 2D chemical structure for CAS 110-00-9

CAS 110-00-9PubChem CID 8029

Furan

Furan is a monocyclic heteroarene with a structure consisting of a 5-membered ring containing four carbons and one oxygen, with formula C4H4O. It is a toxic, flammable, low-boiling (31C) colourless liquid. It has a role as a carcinogenic agent, a hepatotoxic agent and a Maillard reaction product. It is a member of furans, a mancude organic heteromonocyclic parent and a monocyclic heteroarene. — ChEBI

IUPAC name: furan

Molecular formula: C4H4O
Molecular weight: 68.07 g/mol
Exact mass: 68.026214747 Da
XLogP3: 1.3
Topological polar surface area: 13.1 Å²
Hydrogen-bond donors: 0
Hydrogen-bond acceptors: 1
Covalent units: 1
Defined stereocentres: 0

Also known as

Divinylene oxideTetroleFurfuranOxacyclopentadieneOxoleFurane1,4-Epoxy-1,3-butadieneAxole

16 more reported names

NCI-C56202UC0XV6A8N9CHEBI:35559OxycyclopentadieneRefChem:5845203-727-3RCRA waste number U124FurfuraneFuran (98%)Furan (stabilized with BHT)HSDB 89CCRIS 3159EINECS 203-727-3UN2389RCRA waste no. U124UNII-UC0XV6A8N9

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:35559
ChEMBL:CHEMBL278980
EPA DTXSID:DTXSID6020646
PubMed:39171654
PubMed:38160780
PubMed:37517673
PubMed:37488932
PubMed:35750087
PubMed:34450210
PubMed:32758512
PubMed:32251705
PubMed:32174189
PubMed:30203046
PubMed:27402187
PubMed:27387713

Evidence from additional scientific databases

NIH PubChem PUG-View

Exact identifier match8029

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

Autoignition Temperature: 390 °C Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Boiling Point: 90 °F at 758 mmHg (EPA, 1998) Source: CAMEO Chemicals
Boiling Point: 31.5 °C Source: Hazardous Substances Data Bank (HSDB)
Boiling Point: 32.00 °C. @ 758.00 mm Hg Source: Human Metabolome Database (HMDB)
Boiling Point: 31.3 °C Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Boiling Point: 31.5 °C @760 [mm Hg] Source: PAC Chemical Database, U.S. Department of Energy

Color/Form: Colorless liquid, turns brown upon standing; color change is retarded if a small amount of water is added Source: Hazardous Substances Data Bank (HSDB)

Density: 0.9371 at 66.92 °F (EPA, 1998) - Less dense than water; will float Source: CAMEO Chemicals
Density: 0.9731 at 19.4 °C/4 °C Source: Hazardous Substances Data Bank (HSDB)
Density: Density = 0.9514 g/cu cm at 20 °C Source: Hazardous Substances Data Bank (HSDB)
Density: Relative density (water = 1): 0.94 Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Density: 0.9514 @ 20°C Source: PAC Chemical Database, U.S. Department of Energy

Flash Point: Less than 32F (EPA, 1998) Source: CAMEO Chemicals
Flash Point: -32 °F (-35 °C) (Closed cup) Source: Hazardous Substances Data Bank (HSDB)
Flash Point: -35 °C Source: ILO-WHO International Chemical Safety Cards (ICSCs)

LogP: log Kow = 1.34 Source: Hazardous Substances Data Bank (HSDB)
LogP: 1.34 Source: Human Metabolome Database (HMDB)
LogP: 1.34 Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Melting Point: -123 °F (EPA, 1998) Source: CAMEO Chemicals
Melting Point: -85.61 °C Source: Hazardous Substances Data Bank (HSDB)
Melting Point: -85.6 °C Source: Human Metabolome Database (HMDB)
Melting Point: -85.6 °C Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Melting Point: -85.61 °C Source: PAC Chemical Database, U.S. Department of Energy

Odor: Ethereal Source: Hazardous Substances Data Bank (HSDB)

Physical Description: Furan appears as a clear colorless liquid with a strong odor. Flash point below 32 °F. Less dense than water and insoluble in water. Vapors heavier than air. Source: CAMEO Chemicals
Physical Description: Liquid Source: EPA Chemical Data Reporting (CDR)
Physical Description: Colorless liquid with an ethereal odor; darkens on exposure to light and air; [HSDB] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Physical Description: Liquid Source: Human Metabolome Database (HMDB)
Physical Description: CLEAR COLOURLESS LIQUID WITH CHARACTERISTIC ODOUR. TURNS BROWN ON STANDING. Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Refractive Index: Index of refraction: 1.4214 at 20 °C/D Source: Hazardous Substances Data Bank (HSDB)

Solubility: less than 1 mg/mL at 72 °F (NTP, 1992) Source: CAMEO Chemicals
Solubility: Soluble in alcohol and ether Source: Hazardous Substances Data Bank (HSDB)
Solubility: Slightly soluble in chloroform; very soluble in ethanol, ether; soluble in acetone, benzene Source: Hazardous Substances Data Bank (HSDB)
Solubility: In water, 1X10+4 mg/L at 25 °C Source: Hazardous Substances Data Bank (HSDB)
Solubility: 10 mg/mL at 25 °C Source: Human Metabolome Database (HMDB)
Solubility: Solubility in water, g/l at 25 °C: 10 Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Vapor Pressure: 493 mmHg at 68 °F (NTP, 1992) Source: CAMEO Chemicals
Vapor Pressure: 600.0 [mmHg] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Vapor Pressure: 600 mm Hg at 25 °C /from experimentally derived coefficients/ Source: Hazardous Substances Data Bank (HSDB)
Vapor Pressure: Vapor pressure, kPa at 20 °C: 65.8 Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Vapor Pressure: 750 [mm Hg] @31 °C Source: PAC Chemical Database, U.S. Department of Energy

Viscosity: 0.38 cP at 20 °C Source: Hazardous Substances Data Bank (HSDB)
Viscosity: 0.38 mPa*s Source: ILO-WHO International Chemical Safety Cards (ICSCs)

IARC Carcinogenic Agent: Furan Source: International Agency for Research on Cancer (IARC)
IARC Carcinogenic Classes: Group 2B: Possibly carcinogenic to humans Source: International Agency for Research on Cancer (IARC)
IARC Monographs: Volume 63: (1995) Dry Cleaning, Some Chlorinated Solvents and Other Industrial Chemicals Source: International Agency for Research on Cancer (IARC)
Publication Year: 1995 Source: International Agency for Research on Cancer (IARC)
Evaluation Year: 1995 Source: International Agency for Research on Cancer (IARC)
Substance: Furan Source: NTP Technical Reports
NTP Technical Report: TR-402: Toxicology and Carcinogenesis Studies of Furan (CASRN 110-00-9) in F344 Rats and B6C3F1 Mice (Gavage Studies) (1993 ) Source: NTP Technical Reports
Peer Review Date: 03/11/91 Source: NTP Technical Reports
Conclusion for Male Rat: Clear Evidence Source: NTP Technical Reports
Conclusion for Female Rat: Clear Evidence Source: NTP Technical Reports
Conclusion for Male Mice: Clear Evidence Source: NTP Technical Reports
Conclusion for Female Mice: Clear Evidence Source: NTP Technical Reports

Exposure Routes: The substance can be absorbed into the body by inhalation. Source: ILO-WHO International Chemical Safety Cards (ICSCs)

First Aid: Signs and Symptoms of Furan Exposure: Acute exposure to furan may produce dizziness, nausea, vomiting, diarrhea, and anorexia. Irritation and burning of the eyes and skin may occur. Furan vapor is a central nervous system depressant.; Emergency Life-Support Procedures: Acute exposure to furan may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.; Inhalation Exposure:; 1. Move victims to fresh air. Emergency personnel should avoid self-exposure to furan.; 2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.; 3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.; Source: CAMEO Chemicals
ERG2024, Guide 128 (Furan): 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)

Signal: Danger Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
GHS Hazard Statements: H224: Extremely flammable liquid and vapor [Danger Flammable liquids]; H302: Harmful if swallowed [Warning Acute toxicity, oral]; H315: Causes skin irritation [Warning Skin corrosion/irritation]; H332: Harmful if inhaled [Warning Acute toxicity, inhalation]; H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H350: May cause cancer [Danger Carcinogenicity]; H373 **: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]; H412: Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard] Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P273, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P317, P318, P319, P321, P330, P332+P317, P362+P364, P370+P378, 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
Signal: Danger Source: European Chemicals Agency (ECHA)
GHS Hazard Statements: H224 (100%): Extremely flammable liquid and vapor [Danger Flammable liquids]; H302+H332 (40.3%): Harmful if swallowed or if inhaled [Warning Acute toxicity, oral; acute toxicity, inhalation]; H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]; H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]; H332 (93.9%): Harmful if inhaled [Warning Acute toxicity, inhalation]; H341 (99.6%): Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H350 (99.6%): May cause cancer [Danger Carcinogenicity]; H373 (99.2%): May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]; H412 (100%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard] Source: European Chemicals Agency (ECHA)
Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P273, P280, P301+P317, P302+P352, P303+P361+P353, P304+P340, P317, P318, P319, P321, P330, P332+P317, P362+P364, P370+P378, 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 263 reports by companies from 14 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; 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: H224: Extremely flammable liquid and vapor [Danger Flammable liquids]; H331: Toxic if inhaled [Danger Acute toxicity, inhalation]; H351: Suspected of causing cancer [Warning Carcinogenicity]; H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]; H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]; H402: Harmful to aquatic life [Hazardous to the aquatic environment, acute hazard] Source: NITE-CMC
Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P273, P280, P303+P361+P353, P304+P340, P308+P316, P316, P318, P319, P321, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC
GHS Hazard Statements: H224: Extremely flammable liquid and vapor [Danger Flammable liquids]; H331: Toxic if inhaled [Danger Acute toxicity, inhalation]; H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H351: Suspected of causing cancer [Warning Carcinogenicity]; H371: May cause damage to organs [Warning Specific target organ toxicity, single exposure]; H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]; H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure] Source: NITE-CMC
Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P280, P303+P361+P353, P304+P340, P308+P316, P316, P318, P319, P321, P370+P378, P403+P233, P403+P235, P405, and P501 (click each P-code to see the statement) Source: NITE-CMC

NFPA Health Rating: 2 - Materials that, under emergency conditions, can cause temporary incapacitation or residual injury. Source: Hazardous Substances Data Bank (HSDB)
NFPA Fire Rating: 4 - Materials that rapidly or completely vaporize at atmospheric pressure and normal ambient temperature or that are readily dispersed in air and burn readily. Source: Hazardous Substances Data Bank (HSDB)
NFPA Instability Rating: 1 - Materials that in themselves are normally stable but that can become unstable at elevated temperatures and pressures. Source: Hazardous Substances Data Bank (HSDB)

Target Organs: Hepatic Source: EPA Integrated Risk Information System (IRIS)

Toxicity Summary: Furan is a potent hepatotoxin and hepatocarcinogen in rodents, causing hepatocellular adenomas and carcinomas in rats and mice, and high incidences of cholangiocarcinomas in rats at doses ≥ 2 mg/kg bw. A genotoxic mode of action cannot be excluded for furan-induced tumor formation. Furan is metabolized by cytochrome P450 (CYP) enzymes, predominantly CYP2E1, to its major metabolite cis-2-butene-1,4-dial (BDA, maleic dialdehyde), a highly reactive electrophile identified as the key mediator of furan toxicity and carcinogenicity. Furan-mediated effects on glutathione (GSH) levels and cell viability can be suppressed by the CYP inhibitor 1-phenylimidazole and increased by pretreatment of rats with acetone (a CYP2E1-inducing agent), indicating that furan cytotoxicity depends on its metabolic activation. BDA has been shown to react with cellular nucleophiles such as GSH and amino acids and to cause cross-links between thiols and amino groups, giving rise to lactam and pyrrole derivatives. Furan reduced the percentage of DNA in the comet tail in turkey liver fetal hepatocytes. Furan was also shown to induce chromosomal aberrations and sister chromatid exchanges (SCEs) in Chinese hamster o Source: Toxin and Toxin Target Database (T3DB)

Environmental Bioconcentration: BCFs of 0.9-1.5 and <3.2-13 were measured in carp (Cyprinus carpio) at furan concentrations of 1 and 0.1 mg/L, respectively(1). According to a classification scheme(2), these BCFs suggest 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 80(SRC), determined from a structure estimation method(2), indicates that furan is expected to have high mobility in soil(SRC). Volatilization of furan from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 5.4X10-3 atm-cu m/mole(SRC), based upon its vapor pressure, 600 mm Hg(3), and water solubility, 10,000 mg/L(4). Furan is expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). A 4% of theoretical BOD using activated sludge in the Japanese MITI test(5) suggests that biodegradation is not 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 80(SRC), determined from a structure estimation method(2), indicates that furan is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 5.4X10-3 atm-cu m/mole(SRC), derived from its vapor pressure, 600 mm Hg(4), and water solubility, 10,000 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 2.5 hours and 3.3 days, respectively(SRC). According to a classification scheme(6), BCFs of 0.9-1.5 and <3.2-13 measured in carp (Cyprinus carpio) at furan concentrations of 1 and 0.1 mg/L(7), respectively, suggest that bioconcentration in aquatic organisms is low(SRC). A 4% of theoretical BOD using activated sludge in the Japanese MITI test(7) suggests that biodegradation is not 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), furan, which has a vapor pressure of 600 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase furan 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 9 to 10 hours, calculated from its rate constants of 3.83X10-11 to 4.23X10-11 cu cm/molecule-sec(3-5). Furan will also react with nitrate radicals and ozone radicals in the atmosphere with half-lives of 50 minutes and 4.5 to 4.6 days, calculated from rate constants of 1.4X10-12 cu cm/molecule sec(4) and 2.4X10-18(4) to 2.5X10-18(6), respectively. Source: Hazardous Substances Data Bank (HSDB)

Industry Uses: Intermediate Source: EPA Chemical Data Reporting (CDR)

Sources/Uses: Used as a chemical intermediate; [HSDB] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Uses: CHEMICAL INTERMEDIATE FOR TETRAHYDROFURAN Source: Hazardous Substances Data Bank (HSDB)
Uses: Organic synthesis, especially for pyrrole, tetrahydrofuran, thiophene Source: Hazardous Substances Data Bank (HSDB)
Uses: Used mainly in the preparation of specialty chemicals such as alpha-acetylfuran, 2,5-dimethoxy-2,5-dihydrofuran, 2,2-difurylpropane, 2,2-di(tetrahydrofurfuryl)propane, and pyrrole derivatives Source: Hazardous Substances Data Bank (HSDB)
Uses: Furan is ... used in the formation of lacquers, as a solvent for resins, and in the production of agricultural chemicals (insecticides), stabilizers, and pharmaceuticals 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

Source	Result	Checked
NIH PubChem PUG-View	Exact match	2026-08-31

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 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Record details

Chemical name

Furan

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

SCCS opinions

CMR

Category	Carcinogenic	Mutagenic	Reprotoxic
Cat. 1B	✓	—	—
Cat. 2	—	✓	—

Key data

CAS

110-00-9

203-727-3

Annex

Entry number

732

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

Annex II 731