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CHEMINFO Record Number: 656
CCOHS Chemical Name: Dibenzo(a,e)pyrene

Dibenzopyrene (non-specific name)

CAS Registry Number: 192-65-4
RTECS Number(s): QL0175000
Chemical Family: Aromatic hydrocarbon / polycyclic aromatic hydrocarbon / PAH
Molecular Formula: C24-H14


Appearance and Odour:
Yellow needle-like crystals; probably odourless.

Odour Threshold:
Probably odourless

Warning Properties:
POOR - Inadequate warning of exposure to carcinogenic PAHs.

Dibenzo(a,e)pyrene is not produced commercially and does not occur as a pure substance, except as a research chemical (99% purity).(3) More commonly, dibenzo(a,e)pyrene occurs naturally as a minor component of complex mixtures of polycyclic aromatic hydrocarbons (PAHs), which are formed when organic substances such as oil, wood, coal, coal tar creosote, petroleum or petroleum products are burned, heated or pressurized. There are hundreds of different PAHs and they are almost always mixed with many other different products of combustion. This CHEMINFO record reviews the limited specific information which is available for pure dibenzo(a,e)pyrene and is intended to be used to understand the potential hazards and control measures of the research chemical. The available information for dibenzo(a,e)pyrene has been supplemented by general information for PAHs, with caution. This is because there is a wide variation in the toxicity of different PAHs. For example, some PAHs are potent carcinogens, while others are practically non-toxic. PAHs do, however, share certain physical properties, such as stability, low solubility in water and low vapour pressure. The PAH for which most information is available is benzo(a)pyrene (B(a)P) (CHEMINFO record 698).

Uses and Occurrences:
There is no commercial production or known use of this compound except as a research chemical. Polycyclic aromatic hydrocarbons are used widely in cancer research laboratories.
It occurs as a by-product of the incomplete combustion of organic matter and is present in fossil fuel, tobacco smoke and motor vehicle exhaust.(3,9)


Yellow needle-like crystals. Probably odourless. POSSIBLE CANCER HAZARD - may cause cancer based on animal data.


Effects of Short-Term (Acute) Exposure

Pure dibenzo(a,e)pyrene is a dust with an extremely low tendency to form a vapour. Health effects following short-term inhalation exposures have not been described in the literature.
The International Agency for Research on Cancer (IARC) has concluded that dibenzo(a,e)pyrene is a possible human carcinogen. Some other PAHs have been clearly established to be carcinogens, even following brief exposures.(15)

Skin Contact:
Specific information is not available for dibenzo(a,e)pyrene.
Mild irritation has been reported in animal tests using for benzo(a)pyrene, anthracene and pyrene, related PAHs. Contact photosensitization (a condition in which the skin becomes extremely sensitive to sunlight or burns easily) has been reported in animals following contact with anthracene, a related PAH.(5,15)

Eye Contact:
Specific information is not available for dibenzo(a,e)pyrene.
Based on mild skin irritation observed following exposure to some other PAHs in animal tests, eye irritation may also occur.

Specific information is not available for dibenzo(a,e)pyrene.
Animal studies with other PAHs have shown low short-term oral toxicity. Ingestion is not a typical route of occupational exposure.

Effects of Long-Term (Chronic) Exposure

Specific information is not available for dibenzo(a,e)pyrene.

Human population studies have associated PAH exposure with cancer and cardiovascular disease. These studies are limited due to the complexity of the exposures and other factors.(16,17) No specific conclusions can be drawn for dibenzo(a,e)pyrene, as it is not possible to evaluate the contribution of any one PAH to the overall effects of these mixtures.
In animal studies, long-term exposure to some other PAHs have shown minor effects on the liver, kidneys, lungs, blood and/or lymph system.(5,15)

SKIN CONTACT: Specific information is not available for dibenzo(a,e)pyrene.
Occupational exposure to products containing PAHs has resulted in dermatitis (red, thick, cracked and itchy skin).(5)
Photoallergy (increased sensitivity to sunlight) has been attributed to occupational exposure to complex mixtures of PAHs present in coal tars and coal tar pitch volatiles. These effects have also been demonstrated in animal studies with a specific PAH, anthracene.(15)


No studies associating cancer in humans following inhalation, oral or dermal exposure specifically to dibenzo(a,e)pyrene were located.
Several human population studies have shown increased lung, skin or scrotal cancer in humans. These cancers are related to exposure to complex PAH mixtures in combustion products, such as emissions from coke ovens, roofing- tar, chimney soot or products containing PAHs such as shale oil. Since PAHs occur naturally only in these complex mixtures, it is impossible to evaluate the contribution of any particular PAH to human carcinogenicity. Nevertheless, even if one specific PAH is not carcinogenic, it will occur in mixtures with others that are carcinogenic.(3,4,5,15)
The International Agency for Research on Cancer (IARC) has concluded that dibenzo(a,e)pyrene is carcinogenic to animals.(6)

The International Agency for Research on Cancer (IARC) has concluded that this chemical is possibly carcinogenic to humans (Group 2B).

The American Conference of Governmental Industrial Hygienists (ACGIH) has no listing for this chemical.

The US National Toxicology Program (NTP) has listed this chemical as reasonably anticipated to be a human carcinogen.

Teratogenicity and Embryotoxicity:
Specific information is not available for dibenzo(a,e)pyrene. One well studied PAH, benzo(a)pyrene, has been shown to cause teratogenic and embryotoxic effects in animal studies.

Reproductive Toxicity:
Specific information is not available for dibenzo(a,e)pyrene. Benzo(a)pyrene has been shown to cause reduced fertility and reproductive capacity in animal studies.

No human or animal information is available. Dibenzo(a,e)pyrene was mutagenic in a short-term test in bacteria and cultured human cells.

Toxicologically Synergistic Materials:
PAHs have been studied extensively for their ability to act as tumour initiators and/or promoters. Since PAHs occur in complex mixtures of chemicals that may include tumour promoters, their activity as initiating agents is noteworthy in that their presence may lead to an increased risk of cancer, in particular skin cancer.(15)

Potential for Accumulation:
In common with other polycyclic aromatic hydrocarbons (PAHs), dibenzo(a,e)pyrene in pure form is absorbed by inhalation, oral and dermal routes of exposure. PAHs bound to particulate matter, such as carbon black, are poorly absorbed. Absorbed PAHs are distributed rapidly and widely in the body, then metabolized and eliminated. The chief site of metabolism is the hepatobiliary system (liver and bile). The main route of elimination for PAHs and metabolites is the feces, with smaller amounts excreted in the urine.(3,8)


Possible cancer hazard. Take proper precautions to protect your own health before attempting rescue (e.g. wear appropriate protective equipment). Remove source of contamination or move victim to fresh air. Obtain medical advice immediately.

Skin Contact:
Avoid direct contact with this chemical. Wear chemical protective gloves, if necessary. Remove contaminated clothing, shoes and leather goods (e.g. watchbands, belts). Quickly and gently blot or brush away excess chemical. Wash gently and thoroughly with water and non-abrasive soap for at least 5 minutes or until the chemical is removed. Obtain medical advice immediately. Discard contaminated clothing, shoes and leather goods. Do not launder or re-use.

Eye Contact:
Avoid direct contact. Wear chemical protective gloves, if necessary. If particle/dust gets into the eye(s), do not allow victim to rub eye(s). Let the eye(s) water naturally for a few minutes. Have victim look right and left, and then up and down. If particle/dust does not dislodge, flush with lukewarm, gently flowing water for 5 minutes or until particle/dust is removed, while holding eyelid(s) open. DO NOT attempt to manually remove anything stuck to eye(s). Obtain medical advice immediately.

NEVER give anything by mouth if victim is rapidly losing consciousness, is unconscious or is convulsing. DO NOT INDUCE VOMITING. Have victim drink 240 to 300 mL (8 to 10 oz.) of water to dilute material in the stomach. Obtain medical advice immediately.

First Aid Comments:
Provide general supportive measures (comfort, warmth, rest).
All first aid procedures should be periodically reviewed by a doctor familiar with the material and its conditions of use in the workplace.


Flash Point:
Not available

Lower Flammable (Explosive) Limit (LFL/LEL):
Not available

Upper Flammable (Explosive) Limit (UFL/UEL):
Not available

Autoignition (Ignition) Temperature:
Not available

Sensitivity to Mechanical Impact:
Probably not sensitive. Normally stable material.

Sensitivity to Static Charge:
Will not accumulate static charge. Under certain conditions, airborne dibenzo(a,e)pyrene dust can probably explode when ignited by an electrostatic spark or other ignition source.

Combustion and Thermal Decomposition Products:
Carbon dioxide, carbon monoxide

Fire Hazard Summary:
Fires involving PAHs may produce toxic, irritating fumes and gases. Small amounts of dibenzo(a,e)pyrene may be produced in fires involving other organic materials, by incomplete combustion. Under certain conditions, a cloud of PAH dust can probably explode when ignited by a spark or flame. Explosions of PAH dusts have occurred in industry.(11) Dibenzo(a,e)pyrene dust is unlikely to be an explosion hazard because it is used only in very small amounts. The fire hazard of solid dibenzo(a,e)pyrene is probably low when exposed to heat or flame. It probably must be preheated before ignition can occur.

Extinguishing Media:
SMALL FIRES - dry chemical powder, water spray, powder, carbon dioxide. LARGE FIRES - water spray, fog, foam. (DOT recommendations for naphthalene).

Fire Fighting Instructions:
Evacuate area and fight fire from a safe distance or a protected location. Approach fire from upwind to avoid dibenzo(a,e)pyrene.
If possible, isolate materials not involved in the fire, if this can be done without risk, and protect personnel. Avoid generating dust to minimize risk of explosion. Water or foam may cause frothing. The frothing may be violent and could endanger personnel close to the fire. However, a water spray or fog that is carefully applied to the surface of the material, preferably with a fine spray or fog nozzle, will cause frothing that will blanket and extinguish the fire. In addition, water can be used in the form of spray or fog to prevent dust formation, keep fire-exposed containers cool and absorb heat to help prevent rupture. Water spray may also be used to knock down irritating/toxic combustion products which may be produced in a fire. Apply water from as far a distance as possible.
Dibenzo(a,e)pyrene is a possible human carcinogen. Do not enter without wearing specialized protective equipment for the situation. Firefighter's normal protective equipment (Bunker gear) will not provide adequate protection. A full-body encapsulating chemical resistant suit with positive pressure self- contained breathing apparatus (MSHA/NIOSH approved or equivalent) may be necessary.


NFPA - Comments:
NFPA has no listing for this chemical in Codes 49 or 325.


Molecular Weight: 302.38

Conversion Factor:
Not applicable

Physical State: Solid
Melting Point: 241-242 deg C (466-468 deg F); 233-234 deg C (452-453 deg F) (4)
Boiling Point: Not available
Relative Density (Specific Gravity): Not available
Solubility in Water: No information available - probably practically insoluble.
Solubility in Other Liquids: Slightly soluble in acetic acid, acetone, benzene and ethanol. Soluble in hot toluene.
Coefficient of Oil/Water Distribution (Partition Coefficient): Not available
pH Value: Not applicable
Vapour Density: Not applicable
Vapour Pressure: Practically zero at 25 deg C
Saturation Vapour Concentration: Not applicable
Evaporation Rate: Not applicable
Critical Temperature: Not available


Polycyclic aromatic hydrocarbons are normally stable, but can slowly decompose in sunlight and air.

Hazardous Polymerization:
Does not occur

Incompatibility - Materials to Avoid:

NOTE: Chemical reactions that could result in a hazardous situation (e.g. generation of flammable or toxic chemicals, fire or detonation) are listed here. Many of these reactions can be done safely if specific control measures (e.g. cooling of the reaction) are in place. Although not intended to be complete, an overview of important reactions involving common chemicals is provided to assist in the development of safe work practices.

OXIDIZING AGENTS - May react violently or produce toxic/irritating fumes.
STRONG ACIDS (e.g. sulfuric and nitric acids) - Decompose PAHs.

Hazardous Decomposition Products:

Conditions to Avoid:
Static charge, sparks, light

Corrosivity to Metals:
Probably not corrosive

Stability and Reactivity Comments:
PAHs are relatively unreactive, but can be attacked readily by reactive chemicals such as nitric acid, sulfuric acid and chlorine. See reference 10 for some of the chemical reactions and biological degradation techniques of PAHs.


No acute toxicity values are available for dibenzo(a,e)pyrene. Polycyclic aromatic hydrocarbons have generally shown low acute toxicity in experimental animals by all routes of exposure.(5,8)

The International Agency for Research on Cancer (IARC) has concluded that there is sufficient evidence for the carcinogenicity of dibenzo(a,e)pyrene in experimental animals.(3) Skin application of 0.1% and 0.05% dibenzo(a,e)pyrene solution in dioxane three times per week for 12 months resulted in increased skin tumours in mice. Skin injection of 0.6 mg dibenzo(a,e)pyrene in olive oil monthly for 3 months (total dose 1.8 mg) resulted in injection site tumours in 32 of 35 mice. A single injection of 0.6 mg dibenzo(a,e)pyrene resulted in injection site tumours in 20 of 27 mice.(4)


Selected Bibliography:
(1) RTECS record for naphtho(1,2,3,4-def)chrysene. Last updated 9610
(2) HSDB record for dibenzo(a,e)pyrene. Complete update on 96/05/13
(3) IARC Monographs on the evaluation of the carcinogenic risk of chemicals to humans. Vol. 32. IARC, 1983. p. 327-330
(4) IARC Monographs on the evaluation of the carcinogenic risk of chemicals to man : certain polycyclic aromatic hydrocarbons and heterocyclic compounds. Vol. 3. IARC, 1972. p. 201-206
(5) Cavender, F. Aromatic hydrocarbons. In: Patty's Industrial Hygiene and Toxicology. 4th ed. Vol. 2B. John Wiley & Sons, 1994. p. 1378-1442
(6) IARC Monographs on the evaluation of carcinogenic risks to humans. Supplement 7. IARC, 1987. p. 62
(7) NIOSH pocket guide to chemical hazards. NIOSH, June 1994. p. 74-75
(8) Health impacts of polynuclear aromatic hydrocarbons. Noyes Data Corporation, 1981
(9) Lunn, G., et al. Destruction of hazardous chemicals in the laboratory. John Wiley & Sons, 1990.
(10) Laboratory decontamination and destruction of carcinogens in laboratory wastes : some polycyclic aromatic hydrocarbons. (IARC Scientific Publications No. 49). IARC, 1983
(11) Field, P. Explosibility assessment of industrial powders and dusts. Her Majesty's Stationery Office, 1983
(12) Fire protection guide to hazardous materials. 11th ed. National Fire Protection Association, 1994
(13) Report on Carcinogens. 11th ed. US Department of Health and Human Services, Public Health Service, National Toxicology Program
(14) Busby, W., et al. Mutagenicity of benzo(a)pyrene and dibenzopyrenes in the Salmonella Typhimurium TM677 and the MCL-5 human cell forward mutation assays. Mutation Research. Vol. 342 (1995). p. 9-16
(15) Toxicological Profile for Polycyclic Aromatic Hydrocarbons (PAH's). U.S. Department of Health and Human Services. August 1995.
(16) Clavel, J., et al. Occupational exposure to polycyclic aromatic hydrocarbons and the risk of bladder cancer: A French case-control study. International Journal of Epidemiology. Vol. 23, No. 6 (1994). p. 1145-1153
(17) Strom, J., et al. Polycyclic aromatic hydrocarbons and cardiovascular disease - A review of the epidemiologic and toxicologic evidence for an etiologic relationship. Journal of Occupational Medicine and Toxicology. Vol. 2, No. 4 (1993). p. 311-334
(18) NIOSH pocket guide to chemical hazards. NIOSH, June 1994. p. 74-75
(19) Forsberg, K., et al. Quick selection guide to chemical protective clothing. 4th ed. Van Nostrand Reinhold, 2002

Information on chemicals reviewed in the CHEMINFO database is drawn from a number of publicly available sources. A list of general references used to compile CHEMINFO records is available in the database Help.

Review/Preparation Date: 1997-09-12

Revision Indicators:
Carcinogenicity 2002-12-18
Resistance of materials for PPE 2004-04-08
Bibliography 2005-02-02

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