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CAS 1 record

CAS 109-99-9

CAS 109-99-9 matches 1 EU annex record across Annex II–VI of Regulation 1223/2009.

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Chemical identity and properties

PubChem 2D chemical structure for CAS 109-99-9
CAS 109-99-9PubChem CID 8028

Tetrahydrofuran

Oxolane is a cyclic ether that is butane in which one hydrogen from each methyl group is substituted by an oxygen. It has a role as a polar aprotic solvent. It is a volatile organic compound, a member of oxolanes, a saturated organic heteromonocyclic parent and a cyclic ether. — ChEBI

IUPAC name
oxolane
Molecular formula
C4H8O
Molecular weight
72.11 g/mol
Exact mass
72.057514874 Da
XLogP3
0.5
Topological polar surface area
9.2 Ų
Hydrogen-bond donors
0
Hydrogen-bond acceptors
1
Covalent units
1
Defined stereocentres
0

Also known as

FuranidineFuran, tetrahydro-Tetramethylene oxideHydrofuranOxacyclopentane1,4-EpoxybutaneTetrahydrofuranneTetraidrofurano
16 more reported names
TetrahydrofuraanCyclotetramethylene oxideAgrisynth THFButane, 1,4-epoxy-RCRA waste number U213Butane, alpha,delta-oxideNCI-C60560Butane alpha,delta-oxide3N8FZZ6PY4NSC-57858CHEBI:26911RefChem:932807203-726-8Diethylene oxideButylene oxideTetrahydrofurane
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

Evidence from additional scientific databases

NIH PubChem PUG-View
Exact identifier match8028

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

  • First Aid: EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.; SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.; INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) shou Source: CAMEO Chemicals
  • ERG2024, Guide 127 (Tetrahydrofuran): 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)
  • First Aid: (General first aid procedures); Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.; Skin: Water flush promptly - If this chemical contacts the skin, flush the contaminated skin with water promptly. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water promptly. If irritation persists after washing, get medical attention.; Breathing: Respiratory support; Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately. Source: The National Institute for Occupational Safety and Health (NIOSH)
  • Signal: Danger Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
  • GHS Hazard Statements: H225: Highly Flammable liquid and vapor [Danger Flammable liquids]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H351: Suspected of causing cancer [Warning Carcinogenicity] Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
  • Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P261, P264+P265, P271, P280, P303+P361+P353, P304+P340, P305+P351+P338, P318, P319, P337+P317, P370+P378, P403+P233, 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
  • Note: This chemical does not meet GHS hazard criteria for 0.1% (2 of 1661) of reports. Source: European Chemicals Agency (ECHA)
  • Signal: Danger Source: European Chemicals Agency (ECHA)
  • GHS Hazard Statements: H225 (99.8%): Highly Flammable liquid and vapor [Danger Flammable liquids]; H302 (31.6%): Harmful if swallowed [Warning Acute toxicity, oral]; H319 (99.3%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H335 (98.7%): May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]; H336 (23.2%): May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]; H351 (51.5%): Suspected of causing cancer [Warning Carcinogenicity] Source: European Chemicals Agency (ECHA)
  • Precautionary Statement Codes: P203, P210, P233, P240, P241, P242, P243, P261, P264, P264+P265, P270, P271, P280, P301+P317, P303+P361+P353, P304+P340, P305+P351+P338, P318, P319, P330, P337+P317, P370+P378, P403+P233, 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 1661 reports by companies from 91 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Reported as not meeting GHS hazard criteria per 2 of 1661 reports by companies.; There are 90 notifications provided by 1659 of 1661 reports by companies with hazard statement code(s).; 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: Warning Source: NITE-CMC
  • GHS Hazard Statements: H315: Causes skin irritation [Warning Skin corrosion/irritation] Source: NITE-CMC
  • Precautionary Statement Codes: P264, P280, P302+P352, P321, P332+P317, and P362+P364 (click each P-code to see the statement) Source: NITE-CMC
  • Signal: Danger 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: 3 - Liquids and solids that can be ignited under almost all ambient temperature conditions. Materials produce hazardous atmospheres with air under almost all ambient temperatures or, though unaffected by ambient temperatures, are readily ignited under almost all conditions. 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)
  • Toxicity Summary: HUMAN TOXICITY: Data pertaining to the toxicity of tetrahydrofuran (THF) in humans is quite limited. The probable oral lethal dose in humans is 50-500 mg/kg. Severe occipital headaches were reported in the testing for pharmacological properties of THF & among technicians performing animal experiments. Toxicity (TCLo) is expected following exposure to a 2.5% concn of THF. ANIMAL TOXICITY: Animal studies indicate that THF is only "MODERATELY TOXIC" from acute exposure with the lowest reported LD50's of 1900-2900 mg/kg by oral route. Median lethal concns by inhalation varied with the duration of exposure but were >20,000 ppm with all species for exposures of 1 hr or less. Reports of animal studies document irritation of the skin & mucous membranes, including the eyes, nose, & upper respiratory tract, as the predominant effect from lower exposures (about 100-200 ppm). High acute doses (about 25,000 ppm) produced anesthesia with delayed induction & recovery periods, accompanied by a fall in blood pressure & strong respiratory stimulation. The margin of safety between anesthesia & death is small. Other effects recorded are those of damage to liver, kidneys, & lung after prolonged exposur Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Bioconcentration: An estimated BCF of 3 was calculated in fish for tetrahydrofuran(SRC), using a log Kow of 0.46(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests 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), Koc values of 18 and 23(2), indicate that tetrahydrofuran is expected to have very high mobility in soil(SRC). Volatilization of tetrahydrofuran from moist soil surfaces is expected to be an important fate process(SRC) given a Henry's Law constant of 7.05X10-5 atm-cu m/mole(3). Tetrahydrofuran is expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 162 mm Hg at 25 °C(4). Tetrahydrofuran, added to the surface of 2 different soil samples which had been sterilized to prevent microbial degradation, had a disappearance half-life of 5.7 days(5). A 100% of theoretical BOD using activated sludge in the Japanese MITI test(6) suggests that biodegradation is an important environmental fate process in soil(SRC); however, the EEC manometric respirometric method, tested in 22 different laboratories, gave a mean of 34% of the theoretical BOD within 28 days(7). Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Fate: AQUATIC FATE: Based on a classification scheme(1), Koc values of 18 and 23(2), indicate that tetrahydrofuran is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon a Henry's Law constant of 7.05X10-5 atm-cu m/mole(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 13 hours and 6.6 days, respectively(SRC). According to a classification scheme(5), an estimated BCF of 3(SRC), from its log Kow of 0.46(6) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). In the modified MITI screening test, tetrahydrofuran at 100 mg/L was completely biodegraded in 14 days using an activated sludge inoculum(8); however, the EEC manometric respirometric method, tested in 22 different laboratories, gave a mean of 34% of the theoretical BOD within 28 days(9). 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), tetrahydrofuran, which has a vapor pressure of 162 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase tetrahydrofuran is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is 21 to 24 hours(3), calculated from its measured rate constants of 1.62X10-11 to 1.8X10-11 cu cm/molecule-sec(4). Butyrolactone and alpha-hydroxytetrahydrofuran were formed as products during the photooxidation of tetrahydrofuran(5). Tetrahydrofuran will also react with nitrate radicals; the half-life for this reaction in air is 3 days(SRC), calculated from its measured rate constant of 4.88X10-15 cu cm/molecule-sec(6). Tetrahydrofuran is moderately reactive in photochemical smog conditions where nitrogen oxides are present; reactions occur in time scales of hours(7-9). Source: Hazardous Substances Data Bank (HSDB)
  • Consumer Uses: Other; Anti-adhesive/cohesive; Solvent; Laboratory chemicals; Intermediate; Not Known or Reasonably Ascertainable Source: EPA Chemical Data Reporting (CDR)
  • Industry Uses: Anti-adhesive/cohesive; Solvent; Other; Tanning agents not otherwise specified; Monomers; Processing aids not otherwise specified; Fuel agents; Fuel; Fragrance; Catalyst; Not Known or Reasonably Ascertainable; Intermediate; Laboratory chemicals Source: EPA Chemical Data Reporting (CDR)
  • Sources/Uses: Used as a solvent for polymers and resins, a wetting agent for textiles, and a chemical intermediate; [ACGIH] Used as a solvent in inks, adhesives, and lacquers; [HSDB] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
  • Industrial Processes with risk of exposure: Textiles (Fiber & Fabric Manufacturing) [Category: Industry]; Painting (Solvents) [Category: Paint]; Working with Glues and Adhesives [Category: Other]; Plastic Composites Manufacturing [Category: Industry] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
  • Uses: Solvent for high polymers, especially polyvinyl chloride. As reaction medium for Grignard and metal hydride reactions. In the synthesis of butyrolactone, succinic acid, 1,4-butanediol diacetate. Solvent in histological techniques. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: Solvent for fat oils, unvulcanized rubber; for making adipic acid Source: Hazardous Substances Data Bank (HSDB)
  • Uses: Solvent in preparation of printing inks, adhesives, lacquers, & other coatings; Grignard reagent in synthesis of motor fuels, vitamins, hormones, pharmaceuticals, synthetic perfumes, organometallic cmpds, & insecticides. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: Solvent for natural and synthetic resins, particularly vinyls, in topcoating solutions, polymer coating, cellophane, protective coatings, adhesives, magnetic tapes, printing inks, etc., Grignard reactions, lithium aluminum hydride reductions, and polymerizations; chemical intermediate and monomer. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: For more Uses (Complete) data for Tetrahydrofuran (6 total), please visit the HSDB record page. 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
SourceResultChecked
NIH PubChem PUG-ViewExact match2026-08-31

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 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Records for CAS 109-99-9

1 total

How CAS 109-99-9 is used on this site

CAS 109-99-9 is the Chemical Abstracts Service identifier used to pin this page to a specific substance. In the current dataset, 1 EU annex record shares this identifier, which helps you cross-check whether the same substance appears under one regulatory context or several.

Use this page when a supplier specification, SDS or raw-material dossier gives you CAS 109-99-9 and you need to see every linked Annex II–VI record in one place. The entry cards above are the quickest route to concentration limits, warnings, annex placement and product-type conditions.

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A substance identified by CAS 109-99-9 may appear in multiple EU cosmetic regulation annexes when it is subject to different conditions in different contexts. For example, a substance might be restricted under Annex III with specific conditions, and the same CAS might also appear in Annex IV as an approved colorant under separate entry conditions. Each entry must be reviewed individually.

Cross-reference the CAS number against your raw material specification sheets and CoA documents. When a CAS appears in Annex II, verify absence. When it appears in Annex III, verify that concentration limits and product type conditions are met in your formulation. All annex entries sharing this CAS number are listed above.

A CAS number is assigned by the Chemical Abstracts Service (USA) and is globally recognised. An EC number is a European Commission identifier from inventories such as EINECS, ELINCS or the NLP list. Both identifiers may appear in EU cosmetic annex entries. Some substances have both, some have only one, and some older entries may have neither.

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