Benzofuran

log Kow= 2.67

2.67

2.67

2.53

1.078 at 59 °F (NTP, 1992) - Denser than water; will sink

1.0913 @ 25 °C

Relative density (water = 1): 1.09

Not solid @ -18 °C; oil

Colorless, oily liquid

0.1 to 1 mg/mL at 64 °F (NTP, 1992)

Insol in water and aq alkaline solns; miscible with benzene, petroleum ether, absolute alcohol, ether.

Soluble in ethanol.

Solubility in water: none

133 °F (NTP, 1992)

56 °C

56 °C

345 °F at 760 mmHg (NTP, 1992)

174 °C @ 760 mm Hg

BP: 62-63 °C @ 15 MM HG

174.00 °C. @ 760.00 mm Hg

174 °C

less than -0.4 °F (NTP, 1992)

Less than -18 °C

< -18 °C

Slowly polymerizes on standing.

.../Polymerizes/ more rapidly under the influence of heat and under the influence of acidic catalyst.

Warning

H226 (100%): Flammable liquid and vapor [Warning Flammable liquids]

P203, P210, P233, P240, P241, P242, P243, P273, P280, P303+P361+P353, P318, P370+P378, P403+P235, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 65 reports by companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Danger

H350: May cause cancer [Danger Carcinogenicity]

Chemical: Benzofuran

Hazard Traits - Carcinogenicity

Benzofuran: Does not have an individual approval but may be used under an appropriate group standard

This chemical is combustible. (NTP, 1992)

Flammable. Above 56 °C explosive vapour/air mixtures may be formed.

2,3-Benzofuran is a colorless, sweet-smelling, oily liquid made by processing coal into coal oil. It may also be formed during other uses of coal or oil. 2,3-Benzofuran is not used for any commercial purposes, but the part of the coal oil that contains 2,3-benzofuran is made into a plastic called coumarone-indene resin. This resin resists corrosion and is used to make paints and varnishes. The resin also provides water resistance and is used in coatings on paper products and fabrics. It is used as an adhesive in food containers and some asphalt floor tiles. The resin has been approved for use in food packages and as a coating on citrus fruits. We do not know how often the resin is used or whether any 2,3-benzofuran in the coating or packaging gets into the food.

May be toxic to the kidneys and liver; [ICSC] An irritant; Effects in high-dose animal studies include acute tubular necrosis; [MSDSonline]

DHHS/ATSDR; Toxicological Profile for Benzofuran TP-91/04 (1992)

DHHS/NTP; Toxicology & Carcinogenesis Studies of Benzofuran in F344/N Rats and B6C3F1 Mice Technical Report Series No. 370 (1989) NIH Publication No. 90-2825

Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. (NTP, 1992)

Use foam, dry powder, carbon dioxide. In case of fire: keep drums, etc., cool by spraying with water.

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.

PRECAUTIONS FOR "CARCINOGENS": Storage site should be as close as practical to lab in which carcinogens are to be used, so that only small quantities required for ... expt need to be carried. Carcinogens should be kept in only one section of cupboard, an explosion-proof refrigerator or freezer (depending on chemicophysical properties ...) that bears appropriate label. An inventory ... should be kept, showing quantity of carcinogen & date it was acquired ... Facilities for dispensing ... should be contiguous to storage area. /Chemical Carcinogens/

You should keep this material in a tightly closed container under an inert atmosphere, and store it at refrigerated temperatures. STORE AWAY FROM SOURCES OF IGNITION.

PRECAUTIONS FOR "CARCINOGENS": A high-efficiency particulate arrestor (HEPA) or charcoal filters can be used to minimize amt of carcinogen in exhausted air ventilated safety cabinets, lab hoods, glove boxes or animal rooms ... Filter housing that is designed so that used filters can be transferred into plastic bag without contaminating maintenance staff is avail commercially. Filters should be placed in plastic bags immediately after removal ... The plastic bag should be sealed immediately ... The sealed bag should be labelled properly ... Waste liquids ... should be placed or collected in proper containers for disposal. The lid should be secured & the bottles properly labelled. Once filled, bottles should be placed in plastic bag, so that outer surface ... is not contaminated ... The plastic bag should also be sealed & labelled. ... Broken glassware ... should be decontaminated by solvent extraction, by chemical destruction, or in specially designed incinerators. /Chemical Carcinogens/

SMALL SPILLS AND LEAKAGE: If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION. Then, use absorbent paper to pick up all liquid spill material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with 60-70% ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

PRECAUTIONS FOR "CARCINOGENS": There is no universal method of disposal that has been proved satisfactory for all carcinogenic compounds & specific methods of chem destruction ... published have not been tested on all kinds of carcinogen-containing waste. ... summary of avail methods & recommendations ... /given/ must be treated as guide only. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": ... Incineration may be only feasible method for disposal of contaminated laboratory waste from biological expt. However, not all incinerators are suitable for this purpose. The most efficient type ... is probably the gas-fired type, in which a first-stage combustion with a less than stoichiometric air:fuel ratio is followed by a second stage with excess air. Some ... are designed to accept ... aqueous & organic-solvent solutions, otherwise it is necessary ... to absorb soln onto suitable combustible material, such as sawdust. Alternatively, chem destruction may be used, esp when small quantities ... are to be destroyed in laboratory. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": HEPA (high-efficiency particulate arrestor) filters ... can be disposed of by incineration. For spent charcoal filters, the adsorbed material can be stripped off at high temp & carcinogenic wastes generated by this treatment conducted to & burned in an incinerator. ... LIQUID WASTE: ... Disposal should be carried out by incineration at temp that ... ensure complete combustion. SOLID WASTE: Carcasses of lab animals, cage litter & misc solid wastes ... should be disposed of by incineration at temp high enough to ensure destruction of chem carcinogens or their metabolites. /Chemical Carcinogens/

For more Disposal Methods (Complete) data for BENZOFURAN (6 total), please visit the HSDB record page.

PRECAUTIONS FOR "CARCINOGENS": Smoking, drinking, eating, storage of food or of food & beverage containers or utensils, & the application of cosmetics should be prohibited in any laboratory. All personnel should remove gloves, if worn, after completion of procedures in which carcinogens have been used. They should ... wash ... hands, preferably using dispensers of liq detergent, & rinse ... thoroughly. Consideration should be given to appropriate methods for cleaning the skin, depending on nature of the contaminant. No standard procedure can be recommended, but the use of organic solvents should be avoided. Safety pipettes should be used for all pipetting. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": In animal laboratory, personnel should remove their outdoor clothes & wear protective suits (preferably disposable, one-piece & close-fitting at ankles & wrists), gloves, hair covering & overshoes. ... Clothing should be changed daily but ... discarded immediately if obvious contamination occurs ... /also,/ workers should shower immediately. In chemical laboratory, gloves & gowns should always be worn ... however, gloves should not be assumed to provide full protection. Carefully fitted masks or respirators may be necessary when working with particulates or gases, & disposable plastic aprons might provide addnl protection. If gowns are of distinctive color, this is a reminder that they should not be worn outside of lab. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": ... Operations connected with synth & purification ... should be carried out under well-ventilated hood. Analytical procedures ... should be carried out with care & vapors evolved during ... procedures should be removed. ... Expert advice should be obtained before existing fume cupboards are used ... & when new fume cupboards are installed. It is desirable that there be means for decreasing the rate of air extraction, so that carcinogenic powders can be handled without ... powder being blown around the hood. Glove boxes should be kept under negative air pressure. Air changes should be adequate, so that concn of vapors of volatile carcinogens will not occur. /Chemical Carcinogens/

PRECAUTIONS FOR "CARCINOGENS": Vertical laminar-flow biological safety cabinets may be used for containment of in vitro procedures ... provided that the exhaust air flow is sufficient to provide an inward air flow at the face opening of the cabinet, & contaminated air plenums that are under positive pressure are leak-tight. Horizontal laminar-flow hoods or safety cabinets, where filtered air is blown across the working area towards the operator, should never be used ... Each cabinet or fume cupboard to be used ... should be tested before work is begun (eg, with fume bomb) & label fixed to it, giving date of test & avg air-flow measured. This test should be repeated periodically & after any structural changes. /Chemical Carcinogens/

For more Preventive Measures (Complete) data for BENZOFURAN (9 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 680(SRC), determined from a log Kow of 2.67(2) and a regression-derived equation(3), indicates that benzofuran is expected to have low mobility in soil(SRC). Volatilization of benzofuran from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 5.3X10-4 atm-cu m/mole(SRC), using a fragment constant estimation method(3). Benzofuran is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 0.44 mm Hg(4). Based upon studies in water which illustate that benzofuran biodegrades in the presence of creosote-adapted microorganisms(5,6), this compound may also biodegrade in soils if acclimation has occurred(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 680(SRC), determined from a log Kow of 2.67(2) and a regression-derived equation(3), indicates that benzofuran is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 5.3X10-4 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 2 hours and 5 days, respectively(SRC). According to a classification scheme(5), a BCF of 360 for guppies(6), suggests bioconcentration in aquatic organisms is moderate(SRC). Benzofuran has been shown to biodegrade in the presence of creosote-adapted microorganisms(SRC). Benzofuran biodegraded using a enriched culture from a creosote contaminated site(7) where biodegradation of benzofuran was enhanced by the degradation of other creosote compounds(7). Benzofuran was completely removed in combination with toluene, p-xylene, m-xylene, naphthalene, 1-methylnapthalene within the first 12 days of incubation, compared with a 7% loss in the acidified control microcosm(7). After 27 days, complete removal of benzofuran was observed in combination with other primary creosote substituents except 1-methylnapthalene where 95% removal was observed(7). In a study using aerobic groundwater microcosms, benzofuran at 3.3 mg/l degraded completely after 95 days (lag period = 70 days) from an aquifer contaminated with creosote compounds while from a background aquifer, benzofuran degraded after 285 days (lag period = 278 days)(8).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), benzofuran, which has a vapor pressure of 0.44 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere(SRC). Vapor-phase benzofuran 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 10 hours(SRC), calculated from its rate constant of 37X10-12 cu cm/molecule-sec at 25 °C(3). Vapor-phase benzofuran is also degraded in the atmosphere by reaction with ozone(4); the half-life for this reaction in air is estimated to be about 6 days(SRC). Benzofuran absorbs light in the environmental UV spectrum (absorption max = 285 nm)(5); thus it has the potential for direct photolysis(SRC).

The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical. [http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=271-89-6]

Benzofuran has been detected in exhaust gases from both gasoline and diesel engines(1-3). The amount of benzofuran detected in exhaust gases from the combustion of various hydrocarbon fuels ranged from <0.1 to 2.8 ppm(2). Emissions of benzofuran from a diesel-powdered medium duty truck was 53.2 ug benzofuran per km(3). Benzofuran has been detected in the exhaust of a four-stroke outboard motor(4). Benzofuran was qualitatively detected in water effluents collected from an advanced treatment facility in Pomona, CA on Sep 25, 1974(5). Aqueous condensate from a coal gasification facility in Morgantown, WV contained a benzofuran conc of 267 ppb(6).

The liver is a common target organ for substituted furan compounds. Ten days of oral exposure of female mice to a dose of 591 mg/kg/day of 2,3-benzofuran altered the activity of several hepatic enzymes, decreasing the rate of reactions which activate electrophiles and increasing the rate of reactions which deactivate electrophiles.

The urinary excretion of metabolites of 2,3-benzofuran was studied in Sprague-Dawley rats (n = 5) given a single dose of 150 mg/kg i.p. Urine samples were collected at defined intervals up to 7 days postdose and analyzed using (1). H NMR and directly coupled high performance liquid chromatography (HPLC)-NMR, HPLC-(mass spectrometry) MS and HPLC-MS-NMR methods. The principal metabolites were determined to be 2-hydroxyphenylacetic acid and 2-(2-hydroxyethyl)phenyl hydrogen sulfate, representing 24.3 +/- 6.0% and 19.6 +/- 6.4% of the dose, respectively.

...The metabolism of several other substituted furans has been shown to involve oxidation by P-450, with the unsubstituted double bond of the furan ring converted either to an epoxide or to a dialdehyde. Pretreatment with inducers and inhibitors of P-450 modified the toxicity of a single ip injection of 2,3-benzofuran to male mice. Oral exposure to 2,3-benzofuran altered the activity of P-450 and other enzymes in the livers of female mice. These experiments indicate that cytochrome P-450 may be involved in the toxicity of 2,3-benzofuran, but do not provide a clear picture of 2,3-benzofuran metabolism.

The partitioning of 2,3-benzofuran between particulate matter and synthetic alveolar surfactant in vitro was reported to depend upon the chemical nature of the particles. Synthetic lung surfactant was able to dissolve 2,3-benzofuran adsorbed to particles with few active sites, but not 2,3-benzofuran adsorbed to particles with many active sites. These data indicate that inhalation of particles containing 2,3-benzofuran would result in some absorption, depending on the nature of the particles.

Used in the manufacture of coumarone-indene resins; [Merck Index]

Manufacture of coumarone-indene resins.

No large-scale commercial use has been found for pure benzofuran.

(1977) 1.84X10+9 GRAMS

(1979) 9.08X10+2 GRAMS

Isolation from coal tar oils; synthesis by heating phenoxyacetaldehyde with zinc chloride and acetic acid.

...Derived from crude heavy solvent naphtha fraction of coal tar light oil, obtained as byproduct in coking of bituminous coal.

Calcining coumarilic acid (from coumarin) with lime.

Coal tar contains about 0.01% benzofuran, which can be concentrated through distillation to about 15% in alight oil fraction with a boiling range of 165-175 °C. It is recovered either by precipitation as the dibromide or the picrate, or by sulfonation in acetic anhydride, followed by decomposition of the benzofuran derivatives. If the benzofuran fraction is largely free from indene, benzofuran can be concentrated further through either selective extraction or azeotropic distillation with alkylene glycols.

Benzofuran can be synthesized by dehydrogenation and cyclization of 2-ethylphenol.