DIBENZ(a,h)ANTHRACENE

Carcinogens

Semi-Volatile Organic Compound (SVOC)

Other Classes -> Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbon

log Kow = 6.50

6.5

6.88

1.282 (NTP, 1992) - Denser than water; will sink

1.282 g/cu cm

Relative density (water = 1): 1.28

Relative density (water = 1): 1.28

1.282 @25 °C

Colorless plates or leaflets /recrystallized/ from acetic acid

Solution in concentrated sulfuric acid is red

Plates, leaflets from acetic acid; crystals may be monoclinic or orthorhombic

White crystals or pale yellow solid[NOAA; CAMEO Chemicals. Database of Hazardous Materials. Dibenz

less than 1 mg/mL at 66 °F (NTP, 1992)

In water, 2.49X10-3 mg/L at 25 °C

In water, 0.000627 mg/L at 25 °C

In water, 0.00166 mg/L at 24-25 °C (average of 5 measured values ranging from 0.0005 to 0.00249)

In water, 0.0005 mg/L at 27 °C

For more Solubility (Complete) data for Dibenz(a,h)anthracene (6 total), please visit the HSDB record page.

975 °F at 760 mmHg (NTP, 1992)

524 °C

524 °C

524 °C @760 [mm Hg]

Hazardous decomposition products formed under fire conditions - Carbon oxides.[Sigma-Aldrich; Safety Data Sheet for Dibenz

When heated to decomposition it emits acrid smoke and irritating fumes.

511 to 513 °F (NTP, 1992)

269 °C

Reddish needles from benzene; melting point: 214 °C /Dibenz(a,h)anthracene picrate/

267 °C

266.8 °C

Danger

H350: May cause cancer [Danger Carcinogenicity]

P203, P273, P280, P318, P391, P405, and P501 (click each P-code to see the statement)

Danger

H350 (100%): May cause cancer [Danger Carcinogenicity]

P203, P273, P280, P318, P391, P405, and P501 (click each P-code to see the statement)

Hazard Traits - Bioaccumulation; Carcinogenicity; Environmental Persistence

Dibenz[a,h]anthracene is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Dibenz[a,h]anthracene are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Dibenza,hanthracene: Does not have an individual approval but may be used as a component in a product covered by a group standard. It is not approved for use as a chemical in its own right.

The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)

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

Combustible.

This chemical is a combustible solid.

Combustible.

May cause skin photosensitization; A probable human carcinogen; Can be absorbed through skin; [ICSC] Evidence of carcinogenicity, mutagenicity, developmental toxicity, and immunosuppression in experimental animals; Emergency treatment: Polynuclear aromatic hydrocarbons; Acute toxicity of PAHs is low; May cause photosensitivity; May cause cancer after chronic exposure; [HSDB] Causes decreased humoral immune response and changes in hepatic microsomal mixed oxidase in oral toxic-dose studies of mice; [RTECS] May cause skin and eye irritation; [Cerilliant MSDS] See POLYCYCLIC AROMATIC HYDROCARBONS.

DHHS/National Toxicology Program; Report on Carcinogens, Fourteenth Edition: Polycyclic Aromatic Hydrocarbons (November 2016). The Report on Carcinogens is an informational scientific and public health document that identifies and discusses substances (including agents, mixtures, or exposure circumstances) that may pose a carcinogenic hazard to human health. Dibenz(a,h)anthracene (53-70-3) is listed as reasonably anticipated to be a human carcinogen.[Available from, as of November 3, 2016: http://ntp.niehs.nih.gov/pubhealth/roc/index-1.html]

Health & Welfare Canada; Polycyclic Aromatic Hydrocarbons (1979) Report No. 80-EHD-50

USEPA; Ambient Water Quality Criteria Doc: Polynuclear Aromatic Hydrocarbons (Draft) (1980)

U.S. Dept Health & Human Services/Agency for Toxic Substances Disease Registry; Toxicological Profile for Polycyclic Aromatic Hydrocarbons (Update) (1995) NTIS# PB/95/264370

U063; As stipulated in 40 CFR 261.33, when dibenz(a,h)anthracene, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).

Fires involving this material can be controlled with a dry chemical, carbon dioxide or Halon extinguisher. A water spray may also be used. (NTP, 1992)

Use water spray, powder.

Fresh air, rest. Seek medical attention if you feel unwell.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Seek medical attention if you feel unwell.

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.

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical. or carbon dioxide.[Sigma-Aldrich; Safety Data Sheet for Dibenz

Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.[Sigma-Aldrich; Safety Data Sheet for Dibenz

Use water spray, powder.

Use dry chemical, carbon dioxide, water spray, or alcohol extinguishers. ... If material or contaminated runoff enters waterways. notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors, or shows any signs of deforming), withdraw immediately to a secure position. ... The only respirators recommended for firefighting are self-contained breathing apparatuses that have full face-pieces and are operated in a pressure-demand or other positive-pressure mode.

If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire (material itself does not burn or burns with difficulty). If large quantities of combustibles are involved, use water in flooding quantities as spray and fog. Keep run-off water out of sewers and water sources. /Benzo(a)pyrene and dibenzo(ah)anthracene/

Keep container tightly closed in a dry and well-ventilated place. Storage class (TRGS 510): Non-combustible, acute toxic Cat.3 / toxic hazardous materials or hazardous materials causing chronic effects.[Sigma-Aldrich; Safety Data Sheet for Dibenz

Store in a secure poison location. ... Before entering confined space where this chemical may be present, check to make sure that an explosive concentration does not exist. Store in tightly closed containers in a cool, well-ventilated area away from strong oxidizers (such as chlorine, bromine, and fluorine). Sources of ignition, such as smoking and open flames, are prohibited where /dibenz(a,h)anthracene/ is used, handled, or stored in a manner that could create a potential fire or explosion hazard. Metal containers involving the transfer of 5 gallons or more ... should be grounded and bonded. Drums must be equipped with self-closing valves, pressure vacuum bungs, and flame arresters. A regulated, marked area should be established where this chemical is handled, used, or stored in compliance with OSHA Standard 1910.1045. /Coal tar pitch and volatiles/

PRECAUTIONS FOR "CARCINOGENS": Storage site should be as close as practicable 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/

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided. Methods and materials for containment and cleaning up: Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.[Sigma-Aldrich; Safety Data Sheet for Dibenz

Evacuate persons not wearing protective equipment from area of spill or leak until cleanup is complete. Remove all ignition sources. Collect powdered material in the most convenient and safe manner and deposit in sealed containers. Ventilate area after cleanup is complete. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify down stream users of potentially contaminated waters. ...

Land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. /SRP: If time permits, pits, ponds, lagoons, soak holes, or holding areas should be sealed with an impermeable flexible membrane liner./ Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Dike surface flow using woil, sand bags, foamed polyurethane, or foamed concrete. /Benzo(a)pyrene and dibenzo(ah)anthracene/

Water spill: Use natural barriers or oil spill control booms to limit spill travel. Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. Remove trapped material with suction hoses. /Benzo(a)pyrene and dibenzo(ah)anthracene/

For more Cleanup Methods (Complete) data for Dibenz(a,h)anthracene (11 total), please visit the HSDB record page.

SMALL SPILLS AND LEAKAGE: If a spill of this chemical occurs, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with acetone and transfer the dampened material to a suitable container. Use absorbent paper dampened with acetone to pick up any remaining material. Seal your contaminated clothing and the absorbent paper in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with acetone 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.

Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number U063, must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must be evaluated in accordance with EPA 40 CFR Part 261, specifically Subpart B, in order to determine the appropriate local, state and federal requirements for disposal.

Product: Offer surplus and non-recyclable solutions to a licensed disposal company. Contact a licensed professional waste disposal service to dispose of this material. Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber; Contaminated packaging: Dispose of as unused product.[Sigma-Aldrich; Safety Data Sheet for Dibenz

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal, state, and local environmental regulations must be observed. /Coal tar pitch and volatiles/

For more Disposal Methods (Complete) data for Dibenz(a,h)anthracene (11 total), please visit the HSDB record page.

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into sealable containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations. Do NOT let this chemical enter the environment.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.[Sigma-Aldrich; Safety Data Sheet for Dibenz

Precautions for safe handling: Avoid formation of dust and aerosols. Further processing of solid materials may result in the formation of combustible dusts. The potential for combustible dust formation should be taken into consideration before additional processing occurs. Provide appropriate exhaust ventilation at places where dust is formed.[Sigma-Aldrich; Safety Data Sheet for Dibenz

Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.[Sigma-Aldrich; Safety Data Sheet for Dibenz

Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.[Sigma-Aldrich; Safety Data Sheet for Dibenz

For more Preventive Measures (Complete) data for Dibenz(a,h)anthracene (19 total), please visit the HSDB record page.

The average concentration of dibenz(a,h)anthracene in 7 personal air samples of workers employed at a needle coke plant during normal operation was less than 0.01 ug/cu m(1). Dibenz(a,h)anthracene was identified in seven minute personal air samples collected from chimney sweeps during "dirty work" at unreported concentrations(2). Dibenz(a,h)anthracene was detected in personal air samples collected in the furnace area of a silicon carbide process plant at concentrations ranging from (ng/cu m) 7 to 45 for the foreman; 2 to 12 for the crane operator; 16 to 69 for oven workers whose tasks were in close proximity to the oven; and 5 to 24 for oven workers whose tasks did not involve direct work at the oven site(3). Dibenz(a,h)anthracene was detected in personal air samples of 6 workers in a plant producing carbon anodes for aluminum electrolysis, worksite - concentration of dibenz(a,h)anthracene (ug/cu m): forming section - 0.13 to 0.40; paste plant - 0.20 to 0.96; store section (broken green anodes and burned anodes) - 0.03 to 0.10; forming section - 0.35 to 0.83; store section (coke) paste plant - 0.02 to 0.31; and all worksites - 0.03 to 0.79(4).

... The influence of near-ultraviolet light (UVA) on the cytotoxicity and genotoxicity of 7 polycyclic aromatic hydrocarbons (PAH) in larvae of the amphibian Pleurodeles waltl /was evaluated/. Benz[a]anthracene (BA), 7,12-benz[a]anthraquinone (BAQ) and anthracene (Ac) proved to be lethal at low doses (some ppb), and the following order of genotoxicity was observed: BA approximately BAQ > DMBA > DMA (9,10-dimethylanthracene). Ac, AQ (9,10-anthraquinone) and DBA (dibenz[a,h]anthracene) were not found to be clastogenic. In the larvae reared in normal conditions (subdued natural daylight/darkness alternation) or in continuous darkness, the BA derivatives were shown to be more genotoxic than BA itself: DMBA > BAQ > BA; BA (>/= 187.5 ppb) slightly increased the level of micronuclei in circulating erythrocytes, while DMBA was strongly clastogenic, in line with their reported carcinogenicity. In other experiments, rearing media alone (i.e., water containing BA, BAQ or DMBA) were UVA-irradiated for 24 hr, and then tested on larvae in the dark ('IR-UV/dark' conditions). Photodegradation of BA (50 and 100 ppb) gave rise to clastogenic products. By contrast, DMBA (12.5, 25 or 50 ppb) was destroyed by UVA, and we suggested that any potentially mutagenic photoproducts formed were not in sufficient amounts to yield a positive response in the newt micronucleus test.

Carcinogenicity of hydrocarbon mixt predominantly found in automobile exhaust gas condensate was attributed to the syncarcinogenic action of benzo[a]pyrene, dibenz[a,h]anthracene, benz[a]anthracene, and benzo[b]fluoranthene. The 4 carcinogenic hydrocarbons were tested in mice with single dosage levels of 4-12 ug ... It was not possible to demonstrate an inhibitory action of most of the weak-to-inactive hydrocarbons; on the contrary, an additive effect of the two types could be observed. At very high doses (almost 10 times higher than the highest doses selected in the rest of the trial) the group of substances which were supposed to be non-carcinogenic also proved to be biologically effective.

The genotoxicity of 15 polycyclic aromatic hydrocarbons was determined with the alkaline version of the comet assay employing V79 lung fibroblasts of the Chinese hamster as target cells. These cells lack the enzymes necessary to convert PAHs to DNA-binding metabolites. ... 11 PAHs, i.e., benzo[a]pyrene (BaP), benz[a]anthracene, 7,12-dimethylbenz[a]anthracene, 3-methylcholanthrene, fluoranthene, anthanthrene, 11H-benzo[b]fluorene, dibenz[a,h]anthracene, pyrene, benzo[ghi]perylene and benzo[e]pyrene caused DNA strand breaks even without external metabolic activation, while naphthalene, anthracene, phenanthrene and naphthacene were inactive. When the comet assay was performed in the dark or when yellow fluorescent lamps were used for illumination the DNA-damaging effect of the 11 PAHs disappeared. White fluorescent lamps exhibit emission maxima at 334.1, 365.0, 404.7, and 435.8 nm representing spectral lines of mercury. In the case of yellow fluorescent lamps these emissions were absent. Obviously, under standard laboratory illumination many PAHs are photo-activated, resulting in DNA-damaging species. This feature of PAHs should be taken into account when these compounds are employed for the initiation of skin cancer. ...

EC50; Species: Daphnia magna (Water flea) about 4 day old juvenile; Conditions: freshwater, static, 20 °C, pH 8.0, alkalinity 250 mg/L CaCO3; Concentration: 496 ug/L for 24 hr (95% confidence interval: 360-778 ug/L); Effect: intoxication, immobilization /97% purity/

LC50; Species: Daphnia magna (Water flea) age <24 hr neonate; Conditions: freshwater, aquatic, visible light plus UVA, 20 °C; Concentration: 5.6 nM for 48 hr /97% purity/

LC50; Species: Daphnia magna (Water flea) age <24 hr neonate; Conditions: freshwater, aquatic, simulated solar radiation, 20 °C; Concentration: 1.98 nM for 48 hr /97% purity/

LC50; Species: Neanthes arenaceodentata (marine worm); Conditions: static bioassay; Concentration: = >1 ppm for 96 hr

TERRESTRIAL FATE: Based on a recommended classification scheme(1), measured Koc values ranging from 5.7X10+5 to 4.8X10+7(2,3) indicate that dibenz(a,h)anthracene is expected to be immobile in soil(SRC). Volatilization of dibenz(a,h)anthracene from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.4X10-7 atm-cu m/mole(SRC), derived from its vapor pressure, 9.55X10-10 mm Hg(4), and water solubility, 0.00249 mg/L(5). Dibenz(a,h)anthracene is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(4). Degradation half-lives of 361 to 940 days determined in several soil studies(6-8) indicate that biodegradation is not an important environmental fate process in soil(SRC). Dibenz(a,h)anthracene absorbs strongly at wavelengths >290 nm(9) and, therefore, is expected to be susceptible to direct photolysis by sunlight(SRC). The photolysis of dibenz(a,h)anthracene sorbed to the surface of spruce needles follows first-order kinetics with a half-life of 15 hours under sunlight irradiation(10); therefore, photolysis on soil surfaces exposed to sunlight may be an important fate process(SRC).[(1) Swann RL et al; Res Rev 85: 23 (1983) (2) Sims RC, Overcash MR; Res Rev 88: 1-68 (1983) (3) Hawthorne SB et al; Environ Toxicol Chem 25: 2901-2911 (2006) (4) Lei YD et al; J Chem Eng Data 47: 801-806 (2002) (5) USEPA; Hassett JJ et al; Sorption Properties of Sediments and Energy-related Pollutants. EPA-600/3-80-041. Athens, GA: p.103 (1980) (6) Keck J et al; Water Res 23: 1467-76 (1989) (7) Park KS et al; Environ Toxicol Chem 9: 187-95 (1990) (8) Coover MP, Sims RC; Haz Waste Haz Mat 4: 69-82 (1987) (9) NIST; NIST Chemistry WebBook. Dibenz

AQUATIC FATE: Based on a recommended classification scheme(1), measured Koc values ranging from 5.7X10+5 to 4.8X10+7(2,3), indicate that dibenz(a,h)anthracene is expected to adsorb to suspended solids and sediment in water(SRC). Volatilization from water surfaces is not expected(4) based upon an estimated Henry's Law constant of 1.4X10-7 atm-cu m/mole(SRC), derived from its vapor pressure, 9.55X10-10 mm Hg(5), and water solubility, 0.00249 mg/L(6). According to a classification scheme(7), an estimated BCF of 9000(SRC), from its log Kow of 6.50(8) and a regression-derived equation(9), suggests the potential for bioconcentration in aquatic organisms is very high(SRC), provided the compound is not metabolized by the organism(SRC). However, dibenz(a,h)anthracene may not bioconcentrate in aquatic organisms which contain microsomal oxidase, such as fish, as this enzyme enables the rapid metabolism of certain polycyclic aromatic hydrocarbons(10). A BCF of 10 was measured in golden ide fish (Leuciscus idus melanotus) that were exposed over a 3-day period(11). A measured fish biotransformation half-life of 1.63 days has been reported for dibenz(a,h)anthracene(12). Degradation half-lives of 361 to 940 days determined in several soil studies (13-15) indicate that biodegradation may not be an important environmental fate process in water(SRC). Dibenz(a,h)anthracene is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dibenz(a,h)anthracene, which has a vapor pressure of 9.5X10-10 mm Hg at 25 °C(2), is expected to exist primarily in the particulate phase in the ambient atmosphere. One urban air monitoring study found the ratio of particulate phase to vapor phase dibenz(a,h)anthracene to be approximately 10 to 1(3). Vapor-phase dibenz(a,h)anthracene 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 7.7 hours(SRC), calculated from its rate constant of 5.0X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(4). Particulate-phase dibenz(a,h)anthracene may be removed from the air by wet and dry deposition(SRC). Dibenz(a,h)anthracene has been detected in precipitation(5) and in dry atmospheric deposition(6). Dibenz(a,h)anthracene absorbs strongly at wavelengths >290 nm(7) and, therefore, is expected to be susceptible to direct photolysis by sunlight(SRC). The photolysis of dibenz(a,h)anthracene sorbed to the surface of spruce needles follows first-order kinetics with a half-life of 15 hours under sunlight irradiation(8).[(1) Bidleman TF; Environ Sci Technol 22: 361-367 (1988) (2) Lei YD et al; J Chem Eng Data 47: 801-806 (2002) (3) He J, Balasubramanian R; Chemosphere 78: 742-751 (2010) (4) US EPA; Estimation Program Interface (EPI) Suite. Ver. 4.11. Nov, 2012. Available from, as of Aug 24, 2016: http://www2.epa.gov/tsca-screening-tools (5) Manoli E et al; Chemosphere 41: 1845-55 (2000) (6) Bari MA et al; Sci Total Environ 485-486: 180-192 (2014) (7) NIST; NIST Chemistry WebBook. Dibenz

Dibenz(a,h)anthracene was detected in: spinach, 0.3 ppb; tomatoes, 0.04 ppb; cereals, 0.1 to 0.6 ppb; and charcoal-broiled steaks, 0.2 ppb(1). Dibenz(a,h)anthracene was identified, but not quantified in fats and oils(2). It was detected in Canadian: breakfast cereal puffed wheat, 3.0 ppb; wheat bran, 3.6 ppb; barley malt, 1.2 ppb; cooking oil, soya, 0.7 ppb; and corn, 1.1 ppb(3). Dibenz(a,h)anthracene was detected in spinach, 0.3 ppb; salad, 0.6 to 1.0 ppb; kale, 0.1 to 2.6 ppb; tomatoes, 0.04 ppb; and cereals, 0.1 to 0.6 ppb(4). UK, total diets, 1979, range (average) ppb dibenz(a,h)anthracene: cereals, 0.04 to 0.14(0.06), meat, not detected to 0.03(0.01), oils and fats, not detected to 0.23(0.06), fruit and sugar, not detected to 0.03(0.01), vegetables, not detected to 0.03(0.01)(5). 11% of 9 yeast samples contained dibenz(a,h)anthracene at a concentration of 0.9 ppb; refined vegetable oil, 0 to 3 ppb, crude vegetable oil 0 to 19 ppb (max found in coconut oil)(6). Dibenz(a,h)anthracene was detected in: edible oils, 0 to 1.9 ug/kg; vegetables, 0.5 to 2.6 ug/kg; and charcoal-broiled steaks, 0.2 ug/kg(7). Dibenz(a,h)anthracene was detected in the following carrot tissues (concentration in ug/kg dry weight): peel (2.1); outer core (0.6); core (0.6)(8). Dibenz(a,h)anthracene was detected in uncooked carrots, 3.8 ug/kg dry weight; cooked carrots, 3.9 ug/kg dry weight; and frozen carrots obtained from a supermarket in the United Kingdom, 0.6 ug/kg dry weight(8).

Dibenz(a,h)anthracene was detected in (mean concentration, ug/kg): margarine (0.3), mussels (2.2), spinach (0.05), and kale (0.4), The Netherlands (1). The following South Indian foods were found to contain dibenz(a,h)anthracene (concentration, ug/g): cumin seeds (0.509); chappatti, wheat flour item (3.695); calamus (0.129); oil-fried, salted and sun-dried chiles (27.480); oil-fried, salted and sun-dried cluster beans (9.540); decoction made from pyrolysed cumin seeds + mint leaves + cardamom (31.150); aniseeds (0.302); and sundakkai (0.621)(2). It was also detected in smoked Edam cheese, smoked cheddar cheese, smoked sliced chicken, smoked sliced turkey, and smoked sliced ham at 0.1, 0.1, 0.1, 0.4, and 0.1 ppb, respectively(3). Dibenz(a,h)anthracene was detected in fermented and dried smoked sausage and cooked bologna produced in Norway at concentrations ranging from 0.07 to 0.60 and 0.04 to 1.10 ppb, respectively(4). In the industrialized Thessaloniki area of northern Greece median dibenz(a,h)anthracene concentrations in ug/g ranged from 0-0.36 in cabbage, 0.04-0.18 in carrots, 0-0.12 in leeks, 0-0.28 in lettuce, and 0.04-0.19 in endive(5). Dibenz(a,h/a,c)anthracene levels of 2.19-9.50 ug/kg were detected in olive pomace oil(6). In foods collected from Moravia in the Czech Republic in 2003, dibenz(a,h)anthracene was detected in apricot (<0.01-0.07 ug/kg), cauliflower (<0.01-0.03 ug/kg), and cabbage (<0.01-0.06 ug/kg)(7). Dibenz(a,h)anthracene was detected at a mean concentration of 83 ug/kg in lettuce from the Pearl River Delta, South China(8).

The substance can be absorbed into the body by inhalation, through the skin and by ingestion.

Oral (L10) ; inhalation (L10)

In an analysis of 31 human milk samples collected from non-smoking women in Beijing, China during 2005-2006, bibenz(a,h)anthracene was detected at mean, median, minimum and maximum concentrations of 0.129, 0.087, not detectable and 1.30 ng/g fresh weight respectively(1).

IDENTIFICATION AND USE: Dibenz(a,h)anthracene (DBA) forms white crystals or a pale yellow solid. It is used as a research chemical. HUMAN EXPOSURE AND TOXICITY: DBA is a probable human carcinogen. Neuroblastoma risk in a child was increased with higher maternal exposure to DBA. ANIMAL STUDIES: Addition of DBA to food for a total dose of 9-19 mg over a period of 5-7 months in mice led to the appearance of tumors of the forestomach in 7/22 survivors after 1 year; 1 of these tumors was a carcinoma. In a later experiment, 20 back-cross mice receiving 0.4 mg DBA per day orally developed 2 squamous cell carcinomas and 11 papillomas of the forestomach within 406 days. In a similar experiment tumors were produced in the lung, heart, and intestine. Squamous carcinomas of forestomach were induced if emulsion was stabilized against the breaking effect of gastric juices. No tumors were seen among 10 Syrian golden hamsters receiving 20 applications of 0.2% solutions DBA over a period of 10 weeks, 5 of which were alive at 50 weeks. DBA was positive in differential survival assays using DNA-repair-proficient/-deficient strains of bacteria and was mutagenic to Salmonella typhimurium with metabolic activation. In cultured mammalian cells DBA was mutagenic and induced unscheduled DNA synthesis with metabolic activation. It was positive in assays for morphological transformation. In the one available study, it induced sister chromatid exchange but not chromosomal aberrations in vivo. Carcinogenic polycyclic aromatic hydrocarbons can produce an immunosuppressive effect. This was first observed in administration of high doses of 3-methylcholanthrene and DBA to mice. DBA has a "bay-region" structure. It is metabolized by mixed-function oxidases to dihydrodiols that are mutagenic in bacteria and tumorigenic in mouse skin painting assays and when injected into newborn mice. The influence of near-ultraviolet light (UVA) on the DBA cytotoxicity and genotoxicity in larvae of the amphibian Pleurodeles waltl was evaluated and DBA was not found to be clastogenic. ECOTOXICITY STUDIES: Of 121 pigeons which received intramuscular injections of 3 mg DBA were observed for 13 months, 14 developed fibrosarcoma at the injection site. No tumors were found among 32 untreated controls. Intramuscular injection of 0.4% DBA in lard induced sarcomas in 15/31 fowl within 45 months. Injection of 0.3-0.5 mg DBA in olive oil into the kidney of frogs (Rana pipiens) produced renal adenocarcinomas in 26% of survivors compared with 3% of controls.

The ability of PAH's to bind to blood proteins such as albumin allows them to be transported throughout the body. Many PAH's induce the expression of cytochrome P450 enzymes, especially CYP1A1, CYP1A2, and CYP1B1, by binding to the aryl hydrocarbon receptor or glycine N-methyltransferase protein. These enzymes metabolize PAH's into their toxic intermediates. The reactive metabolites of PAHs (epoxide intermediates, dihydrodiols, phenols, quinones, and their various combinations) covalently bind to DNA and other cellular macromolecules, initiating mutagenesis and carcinogenesis. The main carcinogenic metabolite of benzo(a)pyrene is the diol-epoxide trans-9,10-epoxy-7,8-dihydrodiol. (L10, L23, A27, A32)

The average total daily intake of PAHs by a member of the general population has been estimated to be 0.207 ug from air, 0.027 ug from water, and 0.16-l.6 ug from food(1). The total potential exposure to carcinogenic PAHs for adult males in the United States was estimated to be 3 ug/day. Smokers of unfiltered cigarettes may experience exposures twice as high as these estimates(1). /Polycyclic Aromatic Hydrocarbons/

WATER INTAKE: Insufficient data for dibenzo(ah)anthracene. AIR INTAKE: (Assume typical concentration of 2 to 120 pg/cu m, the range of urban/suburban concentration for the western US)(1) 40 to 2400 pg. FOOD INTAKE: 0.00043 ug/kg body wt/day, UK, 1979(2).

U063; As stipulated in 40 CFR 261.33, when dibenz(a,h)anthracene, as a commercial chemical product or manufacturing chemical intermediate or an off-specification commercial chemical product or a manufacturing chemical intermediate, becomes a waste, it must be managed according to Federal and/or State hazardous waste regulations. Also defined as a hazardous waste is any residue, contaminated soil, water, or other debris resulting from the cleanup of a spill, into water or on dry land, of this waste. Generators of small quantities of this waste may qualify for partial exclusion from hazardous waste regulations (40 CFR 261.5).

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 1 lb or 0.454 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV.D.3.b).

Toxic pollutant designated pursuant to section 307(a)(1) of the Federal Water Pollution Control Act and is subject to effluent limitations. /Polynuclear aromatic hydrocarbons (including benzanthracenes, benzopyrenes, benzofluoranthene, chrysenes, dibenz-anthracenes, and indenopyrenes)/

For the maximum protection of human health from the potential carcinogenic effects of exposure to polynuclear aromatic hydrocarbons through ingestion of contaminated water and contaminated aquatic organisms, the ambient water concentration should be zero, based on the nonthreshold assumption for this chemical. However, zero level may not be attainable at the present time. Therefore, the levels which may result in incremental increase of cancer risk over the lifetime are estimated at 1X10-5, 1X10-6, and 1X10-7. The corresponding recommended criteria are 28.0 ng/L, 2.8 ng/L, and 0.28 ng/L, respectively. If these estimates are made for consumption of aquatic organisms only, excluding consumption of water, the levels are 311.0 ng/L, 31.1 ng/L, and 3.11 ng/L, respectively. /Polynuclear aromatic hydrocarbons/.

Several of the biological effects of PAHs, such as enzyme induction of xenobiotic metabolizing enzymes, immunosuppression, teratogenicity and carcinogenicity, are thought to be mediated by activation of the aryl hydrocarbon receptor. This receptor is widely distributed and has been detected in most cells and tissues. There is also evidence that the aryl hydrocarbon receptor acts through a variety of pathways and, more recently, that cross-talk with other nuclear receptors enables cell type-specific and tissue-specific control of gene expression. Translocation of the activated aryl hydrocarbon receptor to the nucleus may require threshold concentrations of the ligand. Various oxidative and electrophilic PAH metabolites are also known to induce enzyme systems via anti-oxidant receptor elements. The biological effects of aryl hydrocarbon receptor and anti-oxidant receptor element signalling involve a variety of cellular responses, including regulation of phase I and II metabolism, lipid peroxidation, production of arachidonic acid-reactive metabolites, decreased levels of serum thyroxine and vitamin A and persistent activation of the thyroid hormone receptor. Aryl hydrocarbon receptor signalling may result in adaptive and toxic responses or perturbations of endogenous pathways. Furthermore, metabolic activation of PAHs produces cellular stress. This in turn activates mitogen mediated protein kinase pathways, notably of Nrf2. The Nrf2 protein dimerizes with Maf oncoproteins to enable binding to an anti-oxidant/electrophilic response element, which has been identified in many phase I/II and other cellular defense enzymes and controls their expression. Therefore, cellular stress may be regulated independently of aryl hydrocarbon receptor-mediated xenobiotic metabolizing enzymes. /Polycyclic aromatic hydrocarbons/

The current understanding of the carcinogenesis of polycyclic aromatic hydrocarbons (PAHs) in experimental animals is almost solely based on two complementary mechanisms: those of the diol epoxide and the radical cation. Each provides a different explanation for the data observed in experimental animals. The diol epoxide mechanism features a sequence of metabolic transformations of PAHs, each of which leads to potentially reactive genotoxic forms. In general, PAHs are converted to oxides and dihydrodiols, which are in turn oxidized to diol epoxides. Both oxides and diol epoxides are ultimate DNA-reactive metabolites. PAH oxides can form stable DNA adducts and diol epoxides can form stable and depurinating adducts with DNA through electrophilic carbonium ions. The inherent reactivities of oxides and diol epoxides are dependent on topology (e.g. bay regions, fjord regions, cyclopenta rings), and the reactivity of diol epoxides is further dependent on factors such as stereochemistry and degree of planarity. Both stable and depurinating adducts are formed primarily with guanines and adenines, and induce mutations (e.g. in ras proto-oncogenes) that are strongly associated with the tumorigenic process. Some mutagenic PAH diols, oxides and diol epoxides are tumorigenic in experimental animals. One-electron oxidation creates radical cations at a specific position on some PAHs. The ease of formation and relative stabilities of radical cations are related to the ionization potential of the PAH. Additional important factors in the radical cation mechanism are localization of charge in the PAH radical cation and optimal geometric configuration, particularly the presence of an angular ring. The radical cation mechanism results in the formation of depurinating DNA adducts with guanines and adenines, which generate apurinic sites that can induce mutations in ras proto-oncogenes, which are strongly associated with tumorigenesis. /Polycyclic aromatic hydrocarbons/

Yields 1,2-dihydro-1,2-dihydroxydibenzanthracene, 3,4-dihydro-3,4-dihydroxydibenzanthracene, 5,6-dihydro-5,6-dihydroxydibenzanthracene, and S-(5,6-dihydro-6-hydroxydibenzanthr-5-yl)glutathione in rats. /From table/

Yields dibenzanthracene-7,14-quinone in mice. /From table/

Yields dibenzanthracene-5,6-oxide in rats. /From table/

Current theories on mechanisms of metabolic activation of polycyclic aromatic hydrocarbons are consistent with a carcinogenic potential for dibenz[a,h]anthracene. Dibenz[a,h]anthracene has a "bay-region" structure. It is metabolized by mixed-function oxidases to dihydrodiols that are mutagenic in bacteria and tumorigenic in mouse skin painting assays and when injected into newborn mice.

For more Metabolism/Metabolites (Complete) data for Dibenz(a,h)anthracene (13 total), please visit the HSDB record page.

Dibenzo(a,h)anthracene has known human metabolites that include dibenzo(a,h)anthracene 3,4-epoxide and dibenzo(a,h)anthracene 1,2-epoxide.

Upon topical application /1 uM/mouse/ to mouse skin, dibenz(a,h)anthracene became bound to DNA in skin at treated area to the extent of 15 pmol/mg DNA. This cmpd showed a max level of binding 72 hr after treatment, compared with 19-24 hr for other polycyclic hydrocarbons similarly tested.

In study reported as abstract, it was suggested that DB(a,h)A or its metabolites cross the placenta.

Dietary absorption efficiencies and elimination rates of acenaphthylene, 1-phenyl naphthalene, 2-methyl anthracene, 9-methyl anthracene, triphenylene, perylene, benzo[b]fluorene, dibenzo[a,h]anthracene, benzo [ghi]perylene and coronene were examined in rainbow trout. Subadult fish were exposed to 10 mg of each chemical over 5 days and polycyclic aromatic hydrocarbon (PAH) levels were monitored during the following 25 days. The results indicated that PAHs were not accumulated by trout through dietary exposure because of the combined effects of poor absorption efficiencies and rapid elimination rates. ...

Used as research chemical; Not commercially produced or used in the US; [HSDB]

There is no ... known use of this compound

PAHs are generally not produced commercially in the United States except as research chemicals. /Polycyclic aromatic hydrocarbons/

Substance listed with specific concentration in tattoo ink and/or permanent make up according to EU Commission Regulation 2020/2081. The concentration limit (by weight) is 0.00005%.

PAHs are released into the environment via the combustion of fossil fuels, coke oven emissions and vehicle exhausts, as well as naturally from forest fires and volcanic eruptions. PAHs from these sources may contaminate nearly water systems. They are also found in coal tar and charbroiled food. (L10)

2023: 200,233 lb

(1978) Not produced commercially in USA

(1982) Not produced commercially in USA

There is no commercial production ... of this compound.

From methyl dinaphthyl ketone.

It has been isolated from coal tar pitch and is found in coke oven effluents.

Wood Product Manufacturing

Dibenz[a,h]anthracene: ACTIVE

Dibenz(a,h)anthracene occurs ubiquitously as a product of incomplete combustion; it also occurs in fossil fuels.

PAHs are a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances, such as tobacco and charbroiled meat. There are more than 100 different PAHs. PAHs generally occur as complex mixtures (for example, as part of combustion products such as soot), not as single compounds. PAHs usually occur naturally, but they can be manufactured as individual compounds for research purposes; however, not as the mixtures found in combustion products. ... Others are contained in asphalt used in road construction. They can also be found in substances such as crude oil, coal, coal tar pitch, creosote, and roofing tar. They are found throughout the environment in the air, water, and soil. They can occur in the air, either attached to dust particles or as solids in soil or sediment. /Polycyclic aromatic hydrocarbons/