Dibenzofuran

168.19

168.19

121100

205-071-3

8U54U639VI

1245

3077

DTXSID2021993

LEAF OR NEEDLES FROM ALCOHOL|WHITE CRYSTALS|Crystalline solid

29329995

13.14000

4.12

Dibenzofuran is a colorless white crystalline solid. (NTP, 1992)

1.0886 g/cm³ @ Temp: 99 °C

86.5 °C

287 °C @ Press: 760 Torr

130 °C

1.699

H2O: <0.1 g/100 mL at 20 ºC;Insoluble in wate(<1 mg/mL). soluble in nonpolar organic solvents.

2-8°C

0.00248 mm Hg @ 25 deg C

5.8 (Air= 1)

Weak, characteristic odor

3.90e-12 cm3/molecule*sec

Sublimeable, volatile in steam; dielectric constant = 3.0 at 100 °C|Enthalphy of sublimation = 84.42 kJ/mol|Heat of fusion = 2.27X10+7 J/kmol|Hydroxyl radical reaction rate constant = 3.90X10-12 cu cm/molecule-sec @ 25 °C

Insoluble in water.

Ethers

DIBENZOFURAN is sensitive to prolonged exposure to light (NTP, 1992).

-5.68X10+9 J/kmol at 25 °C

66.4 kcal/mol at 130-140 °C

Critical temperature = 824 K; critial pressure = 3.64 MPa

III

9

UN3077

3

51/53-22-39/23/24/25-23/24/25-11-20/21/22-63-43-36/37/38-45-67-40

22-24/25-61-29-45-36/37-16-7-7/9-23-53

HP4430000

N,Xn,T,F

This compound is sensitive to prolonged exposure to light.

P210-P260-P280-P301 + P310-P311

H225-H301 + H311 + H331-H370

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.

Wilson SC, Jones KC; Environ Pollut 81 (3): 229-49 (1993). Bioremediation of soil contaminated with polynuclear aromatic hydrocarbons.

Flash point data for this chemical are not available. It is probably combustible. (NTP, 1992)

|Warning|H302 (10.53%): Harmful if swallowed [Warning Acute toxicity, oral]|P264, P270, P273, P301+P312, P330, P391, and P501|Aggregated GHS information provided by 22 companies from 5 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

SMALL SPILLS AND LEAKAGE: Should a spill occur while you are handling this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with 60-70% ethanol and transfer the dampened material to a suitable container. Use absorbent paper dampened with 60-70% ethanol to pick up any remaining material. Seal the absorbent paper, and any of your clothes, which may be contaminated, 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. STORAGE PRECAUTIONS: You should protect this material from exposure to light, and store it in a refrigerator. (NTP, 1992)

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)

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

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Dibenzofuran is included on this list.

Exposure to dibenzofuran may occur from inhalation of contaminated air, or ingesting contaminated drinking water or food. No information is available on the acute (short-term), chronic (long-term), reproductive, developmental, and carcinogenic effects of dibenzofuran in humans or animals. Health effects information is available on the polychlorinated dibenzofurans; however, the U.S. Environmental Protection Agency (EPA) has noted that the biological activity of various chlorinated dibenzofurans varies greatly, thus, risk assessment by analogy to any of these more widely studied compounds would not be recommended. EPA has classified dibenzofuran as a Group D, not classifiable as to human carcinogenicity.

[40 CFR 302.4 (7/1/2001)] Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 100 lb or 45.5 kg. The toll free number of the NRC is (800) 424-8802; In the Washington D.C. metropolitan area (202) 426-2675. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).

Dibenzofuran was identified in fly ash collected from a municipal incinerator in Ontario, Canada(1). Dibenzofuran was found in emissions from a factory producing carbon electrodes; a large gas chromatography peak was evident, but no concns were reported(2). Concn in effluents from a sewage treatment plant in Norway ranged from <57 to 359 ng/l during 1979-80(3). Wastewater from a coal gasification facility estimated to contain 0.5 ppm dibenzofuran(4). Concns in wastewater effluents from coal gasification facilities in Gillette, WY and Morgantown, WV were 0.1 and 72 ppb, respectively(5); concn in a shale oil wastewater was 29 ppb(5). Emissions of dibenzofuran from a diesel-powdered medium duty truck was 28.7 ug dibenzofuran per km in gas-phase and 6.0 ug dibenzofuran per km in the particulate-phase(6).

SOIL: The concn of dibenzofuran was 5.7 mg/kg in a sandy soil taken from a wood processing plant in Northern Germany(1).|SEDIMENT: Dibenzofuran is one of 28 aromatic compounds that has been regularly detected in surface sediments from the Elizabeth River which flows into the Chesapeake Bay(1). It was found in sediment from 2 of 5 Great Lakes tributaries at concns of 1.70 and 9.50 ppm(2). Concns detected in sediments from various sites of a Norwegian fjord receiving industrial effluents ranged from 6.7 to 918.7 ppb dry wt(3). Sediments collected from Lake Pontchartrain in LA in 1980 contained levels of 1.9 ppb dry wt(4). Concns in sediments from Eagle Harbor (near Puget Sound, WA) in 1983, which had been receiving creosote effluents, ranged from 31 to 3600 ug/kg(5). One of 4 sediment samples and none of the 5 soil samples collected in the vicinity of a manufacturing plant in Czechoslovakia that processes crude tar contained dibenzofuran (detection limit = 50 ng/g)(6). The concn in the positive sediment sample was 1315.8 ng/g(6). It was detected in Black River Sediment near Lorain, OH, the site of a coking plant associated with a steel mill(7). In sediment samples taken from Lake Michigan (between 1991-1993), the concn of dibenzofuran ranged from 9.59 to 41.25 ng/g dry wt(8). The concns of dibenzofuran in sediment cores in northern New Jersey waterways were (waterway, frequency of detection, median using half of detection limit as concn in samples where substance was not detected (ppm), maximum detected (ppm)): Arthur Kill (n=24), 21%, 0.65, 6.0; Hackensack River (n=12), 17%, 0.58, 0.45; Kill Van Kull (n=12), 0%, 0.44, -; Newark Bay (n=45), 7%, 0.60, 13; Passaic River (n=95), 0.3%, 0.65, 74(9). The frequencies of detection and medians must be treated with caution due, in part, to the high variability in detection limits (as high as 57 ppm for one sample) which were attributed to matrix effects in the highly contaminated sediment (9). Sediment collected from Georges Bank (off Martha's Vineyard, MA) in 1982 had dibenzofuran levels of 0.94 ug/kg(10). Dibenzofuran was detected, but not quantified in Kondo Bay, Japan, a body of water that received untreated industrial and municipal waste(11).

URBAN/SUBURBAN: The concn of dibenzofuran was measured with ground level 12-hr high volume samplers in Minneapolis and Salt Lake City between Nov 1988 and Feb 1989 when wood burning would be expected to contribute to atmospheric pollution(1). Hardwood is burned in Minneapolis and softwood in Salt Lake City(1). Dibenzofuran concns at various types of sites were (site description, number of sites, concn): suburban residential (Minneapolis), 5, 13-31 ng/cu m; city res (Minneapolis), 3, 6.5-16 ng/cu m; non-res downtown (Minneapolis), 3, 10-16 ng/cu m; res suburban (Salt Lake City) 3, 22-28 ng/cu m; city res (Salt Lake City), 6, 11-76 ng/cu m; non-res downtown (Salt Lake City), 2, 10-14 ng/cu m(1). The concn of dibenzofuran in the gas-phase in the ambient air of Portland, OR in Feb-Apr 1984 ranged from 13 to 25 ng/cu m(2); the particulate phase concn ranged from 0 to 0.35 ng/cu m(3). The mean concns of dibenzofuran in the gas and particulate phases in Portland were 19 and 0.1 ng/cu m, respectively indicating that only 2.4% of the dibenzofuran was attached to particles(4). A 24-hr air sample collected in December, 1986 in Whitehorse, Yukon contained 2 ppm of dibenzofuran(5).|INDOOR: The concn of dibenzofuran in the air of Finnish saunas ranged from 0.15 to 5.5 ug/cu m(1). The gas-phase concn was generally 5 to 10 times greater than that in the particle phase(1).|RURAL/REMOTE: In 1988, dibenzofuran was qualitatively identified in air at a forest site in West Germany, studied because of severe damage to spruce trees over the previous decade(1).|SOURCE DOMINATED: Ambient air concns ranging from 1.1 to 112.2 ng/cu m were detected in the air of an industrial town in Finland(1). Air monitoring in August and September, 1989 in the vicinity of a manufacturing plant in Czechoslovakia that processes crude tar resulted in 6 of 8 samples containing dibenzofuran concns of 58.9 to 199.3 ng/cu m(2).

Dibenzofuran occurs at normal levels of 0.19-1.50 wt% of dry tar in commercial coal tars(1). A heavy distillate formed during the processing of a WV coal contained 1.4 mg/g dibenzofuran(2). Cigarette smoke and wood smoke contained 2 ppm and 1 ppm of dibenzofuran, respectively(3).

LD50 Guinea pig (Hartley, male, 3-4 wk old) oral 5-10 ug/kg bw/30 days /2,3,7,8-tetrabromodibenzofuran/

/FIELD STUDIES OTHER TERRESTRIAL SPECIES/ The effects of eight polycyclic aromatic compounds (PACs) on the survival and reproduction of the enchytraeid worm Enchytraeus crvpticus were investigated in an agricultural soil with an organic carbon content of 1.6%. With the exception of acridine, which showed a strong binding to the test soil and a subsequent low toxicity, polycyclic aromatic hydrocarbons and neutral N-, S-, O-monosubstituted analogues showed a similar toxicity to the enchytraeids. Concentrations estimated to give a 10% reduction of reproductive output (EC10 values) were based on measured initial concentrations and were, for acridine, 310 mg/kg; for carbazole, 19 mg/kg; for dibenzofuran, 36 mg/kg, for dibenzothiophene, 40 and 45 mg/kg (two tests); for fluoranthene, 15 mg/kg; for fluorene, 25 mg/kg; for phenanthrene, 40 mg/kg; and for pyrene, 11 mg/kg.|/FIELD STUDIES OTHER TERRESTRIAL SPECIES/ The effects of eight polycyclic aromatic compounds on the survival and reproduction of the collembolan Folsomia fimetaria L. were investigated in a well-characterized Danish agricultural soil. With the exception of acridine, polycyclic aromatic hydrocarbons (PAHs) and neutral N-, S-, and O-monosubstituted analogues showed similar toxicities to soil collembolans when the results were expressed in relation to total soil concentrations (mg/kg). The estimated concentrations resulting in a 10% reduction of reproductive output (EC10 values) were based on measured initial concentrations and were for acridine 290 mg/kg, carbazole 10 mg/kg, dibenzofuran 19 mg/kg, dibenzothiophene 7.8 mg/kg, fluoranthene 37 mg/kg, fluorene 7.7 mg/kg, phenantrene 23 mg/kg, and pyrene 10 mg/kg. When the EC10 values were converted to soil pore-water concentrations, they showed a highly significant correlation (r2 = 0.71, p < 0.01) to no-observed-effect concentrations for the freshwater crustacean Daphnia magna, as estimated by a quantitative structure activity relation (QSAR) for baseline toxicity (nonpolar narcosis). Only carbazole and acridine were more than two times more toxic (4.9 and 3.1, respectively) than expected from the Daphnia QSAR data.

Identification of some polar polycyclic cmpd in emissions from brown coal fired residential stoves /including detection of dibenzofuran/.|Dibenzofuran's presence in coal-tar, as a component of heat-transfer oils, as a carrier for dyeing and printing textiles, as an intermediate for production of dyes, and as an antioxidant in plastics (1) may result in its release to the environment through various waste streams(SRC). Dibenzofuran is a component of coal tar (mainly in the wash or creosote oil fraction in the primary distillation of coal tar) which is made into creosote which is widely used as a wood preservative(2,3). Dibenzofuran may be present in emissions from creosote-treated wood(SRC). Dibenzofuran may be released in wastewater, solid waste, and emissions at wood preserving facilities, coking oven, and other facilities that produce or use coal tar and coal tar products(SRC). Leachates from commercial coal tar contain dibenzofuran(4). Sources of dibenzofuran release to the atmosphere include the combustion of coal, biomass, refuse, diesel fuel, and residual oil, coal gasification, and tobacco smoke(5-8).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 4,200(SRC), determined from a log Kow of 4.12(2) and a regression-derived equation(3), indicates that dibenzofuran is expected to have slight mobility in soil(SRC). Volatilization of dibenzofuran from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.1X10-4 atm-cu m/mole(SRC), derived from its vapor pressure, 0.00248 mm Hg(4), and water solubility, 3.1 mg/l(5). However, adsorption to soil is expected to attenuate volatilization(SRC). Dibenzofuran is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Photoreactor studies indicate that photodegradation may occur in surface soil but degradation rates appear to be slow(6). Screening tests in water indicate that dibenzofuran is not likely to be readily biodegradable(SRC). Dibenzofuran, present at 100 mg/l, reached 0% of its theoretical BOD in 4 weeks using an activated sludge inoculum at 30 mg/l and the Japanese MITI test(7). However, indigenous soil microorganisms at contaminated sites can degrade dibenzofuran if stimulated(8,9). At a creosote-contaminated site, the concn of dibenzofuran at 8 locations (mean, 652 mg/kg) was reduced by an avg of 83% in 4 months(9).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 4,200(SRC), determined from a log Kow of 4.12(2) and a regression-derived equation(3), indicates that dibenzofuran 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 2.1X10-4 atm-cu m/mole(SRC), derived from its vapor pressure, 0.00248 mm Hg(4), and water solubility, 3.1 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 5 hours and 7 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column(SRC). The estimated volatilization half-life from a model pond is 82 days if adsorption is considered(6). According to a classification scheme(7), BCF values for fish of 524 to 947(5,8) are high and from 1,100 to 2,420(5,8,9) are very high(SRC). However, rapid elimination of dibenzofuran would reduce the BCF potential(SRC). Over 97% of the accumulated dibenzofuran was eliminated in 2 days during depuration tests in fathead minnow(10). Screening tests indicate that dibenzofuran is not readily biodegradable(SRC). Dibenzofuran, present at 100 mg/l, reached 0% of its theoretical BOD in 4 weeks using an activated sludge inoculum at 30 mg/l and the Japanese MITI test(8). However, dibenzofuran was degraded in a few days in laboratory studies using subsurface materials which had been contaminated by creosote chemicals(11). The rate of dibenzofuran degradation in studies using pristine subsurface materials was relatively slow and not much faster than in autoclaved controls, 3.9% per week(11). Restriction of oxygen supply in the non-sterile experiments significantly lowered the degradation rate(11). Once microbial adaptation had occurred, dibenzofuran rapidly biotransformed as long as an adequate oxygen supply was present(11).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dibenzofuran, which has a vapor pressure of 0.00248 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere(SRC). However, a small fraction (about 2.4%) exists in the particulate phase(3-5). Vapor-phase dibenzofuran 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 4 days(SRC), calculated from its rate constant of 3.9X10-12 cu cm/molecule-sec at 25 °C(6). For particle-associated dibenzofuran, the dominant tropospheric removal processes are expected to be wet and dry deposition; a tropospheric lifetime of >10 days is expected which is sufficient for long-range transport to occur(7). Rainwater monitoring indicates that both vapor-phase and particulate dibenzofuran are removed from air via wet deposition(3,4). Washout ratios (concn in rainwater/concn in air) are approximately 1000(5). Dibenzofuran absorbs little UV light above 300nm, but UV absorption rises sharply below 300 nm(7), indicating a potential for direct photolysis in the atmosphere(SRC).

The rate constant for the vapor-phase reaction of dibenzofuran with photochemically-produced hydroxyl radicals is 3.9X10-12 cu cm/molecule-sec at 25 °C(1). This corresponds to an atmospheric half-life of about 4 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Vapor-phase reaction of dibenzofuran with ozone and nitrate radicals result in atmospheric half-lives of >142 days and >4.9 years, respectively(1), which are negligible compared with the reaction of dibenzofuran with hydroxyl radicals(SRC). Dibenzofuran absorbs little UV light above 300 nm, but UV absorption rises sharply below 300 nm(2), indicating a potential for direct photolysis in the environment(SRC). Soil studies indicate that there may be significant degradation in soil that are attributable to photochemical reactions(2). Reaction rates determined for some systems indicate that half-lives are of the order of months(2). The soil itself was more of a determinant of photoreactivity than amendments in the soil; reactivity was related to soil color and surface reflectance(2). Dibenzofuran is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(3).

1.51e+03|Bioconcentration factors (BCF) for dibenzofuran were measured during a 33-day model ecosystem study: alga, 82; snail, 2,858; mosquito, 2,094; fish, 947(1). Equilibrium BCFs in fathead minnows ranged from 1,100 to 1,700 during 28-day flow-through experiments; equilibrium concns were reached after 2 to 4 days of exposure(1). At initial dibenzofuran concns of 5 and 50 ug/l, BCF values for guppies ranged from 524 to 2,420 and 848 to 2,200, respectfully, over a 8-week period(2). Over 97% of the accumulated dibenzofuran was eliminated in 2 days during depuration tests in fathead minnow(3). A log BCF of 3.54 was measured for guppies (Poecilia reticulata)(4). Sea lamprey taken from the Broadhead Creek site (near a coal gasification plant contaminated with coal-tar in Stroudsburg, PA) had a BCF for dibenzofuran of 7.3 liters/kg(5). According to a classification scheme(6), BCF values for fish of 524 to 947(1,2) are high and from 1,100 to 2,420(1,2) are very high(SRC).

8.13e+03 L/kg|The Koc of dibenzofuran is estimated as 4,200(SRC), using a log Kow of 4.12(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that dibenzofuran is expected to have slight mobility in soil(SRC). Monitoring of dibenzofuran in contaminated groundwater beneath an abandoned creosote facility in Conroe, TX has suggested that leaching of dibenzofuran may be much more important than predicted from estimation methods, although soil from this location had a very low organic content and other co-contaminants present(4). Sorption of creosote compounds (including dibenzofuran) were measured on natural clayey till soil column(5); a Kd of 4.31 l/kg was measured for dibenzofuran (in the presence of other creosote compounds)(5).

The Henry's Law constant for dibenzofuran is estimated as 2.1X10-4 atm-cu m/mole(SRC) derived from its vapor pressure, 0.00248 mm Hg(1), and water solubility, 3.1 mg/l(2). This Henry's Law constant indicates that dibenzofuran is expected to volatilize from water surfaces(3). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec)(3) is estimated as 5 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 7 days(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column(SRC). The estimated volatilization half-life from a model pond is 82 days if adsorption is considered(4). Dibenzofuran's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). However, volatilization from moist soil surfaces is expected to be attenuated by adsorption to soil(SRC). Dibenzofuran is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

GROUNDWATER: Dibenzofuran concns ranging from 0.8-424.7 ppb have been detected in groundwater sampled from various sites beneath an abandoned creosote facility in Conroe, TX during 1982-1983 monitoring(1). Similar monitoring beneath a wood-preserving facility in Pensacola, FL found levels of 0.01-0.49 ppm(2). Another study at the Pensacola site found that the concn of dibenzofuran in ground water (6.1 m deep wells) in the sand and gravel aquifer with down-gradient distance from a surface impoundment was (distance from source, concn): 6 m, 0.30 mg/l; 53 m, 0.04 mg/l; 99 m, 0.16 mg/l; 122 m, <0.10 mg/l; 150 m, <0.10 mg/l(3). Another investigator found that the dibenzofuran concn at the well 6 m from the contamination source was 0.62 mg/l at 6.1 m depth and the concn at the well 53 m from the source was 0.31, 0.19 and 0.27 mg/l at a depth of 3.3, 5.8, and 11.0 m, respectively(4). It should be noted that a less permeable silt-clay layer extends into the sand aquifer between 6 and 15 m depth. Dibenzofuran was detected, but not quantified, in upper level groundwater beneath a coal-tar distillation facility in St. Louis Park, MN(5). Dibenzofuran was detected in groundwater at 3 creosote-contaminated sites in Denmark with concns ranging from not detected (detection limit = 0.05 ug/l) to 31 ug/l(6).|DRINKING WATER: Dibenzofuran was qualitatively identified in drinking water collected from Cincinnati, OH in Oct 1978 and Philadelphia, PA in Feb 1976(1). Samples of Japanese tap water have been found to contain dibenzofuran levels of 1.0 to 56.2 ng/l(2). Various samples of Nordic tap water contained levels of 0.43 to 18 ng/l(3).|SURFACE WATER: Dibenzofuran has reportedly been detected in the surface waters of Lake Erie(1). Dibenzofuran was detected in 12 of 17 waters sampled at the Donana National Park, Spain; concns ranged from 0.001 to 0.041 ug/l, with a median of 0.002 ug/l(2). None of the 4 water samples collected in the vicinity of a manufacturing plant that processes crude tar in Czechoslovakia contained dibenzofuran (detection limit = 50 ng/g)(3).|RAIN/SNOW: The concn of dibenzofuran in the dissolved phase of rain collected in Portland, OR in Feb 1984 ranged from 9.9 to 26 ng/l(1); the particulate phase concn in the rainwater ranged from 0 to 2.1 ng/l(2).

The concn of dibenzofuran detected in Finnish, margarines, and vegetable oils ranged from 0.08 to 0.64 ug/kg(1). The mean concn of dibenzofuran in various Finnish cereal products were (product, concn in ug/kg): bolted wheat flour (n=7), 2.1; bolted rye flour (n=1), 1.4; rolled oats (n=2), 4.1; milled oats (n=3), 2.6; milled wheat (n=19), 1.0; bran (n=1), 4.7(2). The concn of dibenzofuran in smoked oats, barley and beans was 160 ug/kg when the wet grain was exposed to smoke and then milled and 3.1 ug/kg when the bran was separated after smoking and before milling(2).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 3,292 workers (number female workers is unspecified) are potentially exposed to dibenzofuran in the US(1). Occupational exposure to dibenzofuran may occur through inhalation and dermal contact, particularly at sites where coal tar, coal tar derivatives, and creosote are produced and used (e.g., the handling of creosote-treated wood)(2,3). Approximately 4,000 workers in the US were employed at facilities that used creosote as a wood preservative in the late 70s, including an estimated 100 workers employed in commercial thermal and dip treatment operations(3). The workplace air in a carbon-paste plant in Norway was found to contain a dibenzofuran particulate concn of 0.7-1.8 ug/cu m(4). Monitoring of the workplace air in an aluminum reduction plant in Norway found gas-phase dibenzofuran levels of 0.44-61.0 ug/cu m and particulate phase levels of 0.02-0.14 ug/cu m(5). Only cleaning chamber workers (n=3) were exposed to detectable levels of dibenzofuran at a Finnish wood impregnation plant, 0.7 mg/cu m(6). Monitoring data indicate that the general population may be exposed to dibenzofuran via inhalation of ambient air and dermal contact with wood products containing dibenzofuran(SRC).

In EPA's National Human Adipose Tissue Survey, 46 FY82 composite samples of human adipose tissue representing various age groups and geographical areas were analyzed(2). Dibenzofuran was present in 3% of samples.

22.39 Days

tricyclic hydrocarbons /such as dibenzofuran/ induce Cyp1a2 gene expression in B6C3F1 mice via an Ah receptor-independent pathway.

Fluorene and acenaphthalene (indicated by a higher melting point than 82.8 °C)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Inhalation of material may be harmful. Contact may cause burns to skin and eyes. Inhalation of Asbestos dust may have a damaging effect on the lungs. Fire may produce irritating, corrosive and/or toxic gases. Some liquids produce vapors that may cause dizziness or suffocation. Runoff from fire control may cause pollution. (ERG, 2016)

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) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing. INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

dibenzofuran

99+%; technical, 90%

Dibenzofuran: ACTIVE|Dibenzofuran can be synthesized by dehydrogenation of phenol at 450 °C; by oxidative dehydrogenation of phenol and cyclization of 2-cyclohexenylcyclohexanone; by cyclization of diphenyl ether in the presence of palladium(II) acetate; or by the pyrolysis of phthalic anhydride with furan. As sufficient quantities of dibenzofuran can be produced from coal tar, these syntheses are not industrially applied.

Method: EPA-EAD 1625, Semivolatile Organic Compounds by Isotope Dilution GC/MS; Analyte: dibenzofuran; Matrix: water; Detection Level: 10 ug/l.|Method: EPA-OSW 8270D, Semivolatile Organic Compounds GC/MS; Analyte: dibenzofuran; Matrix: solid waste matrices, soils, air sampling media and water samples; Detection Level: 10 ug/l.|Method: DOE OM100R, Semivolatile Organic Compounds in Multimedia Samples by Capillary Column Ion Trap MS; Analyte: dibenzofuran; Matrix: solid waste matrices, soils and groundwater; Detection Level: 45 ug/l.|Method: 8275A, Semivolatile Organic Compounds (PAHs and PCBs) ... Thermal Extraction/Gas Chromatography/Mass Spectrometry; Analyte: dibenzofuran; Matrix: soils, sludges and solid wastes; Detection Level: 0.01-0.05 mg/kg.|Method: 8410, Gas Chromatography/Fourier Transform Infrared Spectrometry for Semivolatile Organic: Capillary Column; Analyte: dibenzofuran; Matrix: wastewater, soils and sediments, and solid wastes; Detection Level: 20 ug/l.

Hazardous Air Pollutants (HAPs)