| Chemical Abstract Number (CAS #) |
53703
|
|---|
| Synonyms | Dibenzo(a,h)anthracene |
|---|
Dibenz(a,h)anthracene | 1,2:5,6-Dibenzanthracene |
| Analytical Methods |
EPA Method 525 |
|---|
EPA Method 610 |
EPA Method 625 |
EPA Method 8100 |
EPA Method 8250A |
EPA Method 8310 |
| Molecular Formula | C22H14 |
|---|
| Use | RESEARCH CHEMICAL
No known use of this compound
|
|---|
| Apparent Color | COLORLESS PLATES OR LEAFLETS RECRYSTALLIZED FROM ACETIC
ACID; SOLN IN CONCENTRATED SULFURIC ACID IS RED; CRYSTALS MAY BE
MONOCLINIC OR ORTHORHOMBIC
|
|---|
| Melting Point | 266 DEG C
|
|---|
| Molecular Weight | 278.33
|
|---|
| Density | 1.282
|
|---|
| Environmental Impact | Dibenz(a,h)anthracene's (DBahA) release to the environment is quite general since it is a
ubiquitous product of incomplete combustion. It is largely associated with particulate matter,
soils, and sediments. Its presence in places distant from primary sources indicates that it is
reasonably stable in the atmosphere and capable of long distance transport. If it is released to soils
it will be expected to adsorb very strongly to the soils and will not be expected to leach to the
groundwater, hydrolyze or evaporate from soils or surfaces. It will be subject to biodegradation in
soils with reported half-lives of 18 and 21 days. If DBahA is released to water it will be expected
to adsorb very strongly to sediments and particulate matter and to bioconcentrate in aquatic
organisms which lack microsomal oxidase (this enzyme enables the rapid metabolism of certain
polycyclic aromatic hydrocarbons). Based on limited data from laboratory screening tests using
settled domestic wastewater and activated sludge, DBahA may be subject to biodegradation in
natural waters. Since DBahA absorbs solar radiation strongly, it may be subject to direct
photolysis in natural waters. However, adsorption may significantly retard photolysis as the
photosensitivity of polyaromatic hydrocarbons is strongly dependent upon the nature of the
surface upon which the compound is adsorbed. It will not hydrolyze and should not evaporate
from water. If released to the atmosphere it will likely be associated with particulate matter and
may be subject to moderately long range transport, depending mainly on the particle size
distribution and climatic conditions which will determine the rates of wet and dry deposition. Its
presence in areas remote from primary sources demonstrates the potential for this long range
transport as well as DBahA's considerable stability in the air. It may be subject to direct photolysis
in the atmosphere; however, adsorption may significantly retard photolysis as the photosensitivity
of polyaromatic hydrocarbons is strongly dependent upon the nature of the surface upon which
the compound is adsorbed. The estimated vapor phase half-life in the atmosphere is 1.00 day as a
result of reaction with photochemically produced hydroxyl radicals. Human exposure will be from
inhalation of contaminated air and consumption of contaminated food and water.
|
|---|
| Environmental Fate | TERRESTRIAL FATE: If dibenz(a,h)anthracene is released to the soil, it will adsorb
very strongly to the soil and will not be expected to leach to the groundwater. It will not
hydrolyze or evaporate from soils or surfaces. It will be subject to biodegradation in soil systems
with reported half-lives of 18 and 21 days .
AQUATIC FATE: If dibenz(A,H)anthracene (DBahA) is released to water, it will be expected
to adsorb very strongly to sediments and particulate matter. It will not hydrolyze and volatilization
will not be an important process. It will be expected to bioconcentrate in aquatic organisms which
lack microsomal oxidase (this enzyme enables the rapid metabolism of certain polycyclic aromatic
hydrocarbons). No information was found on the biodegradation of DBahA in natural waters;
however, based on limited data from laboratory screening tests using settled domestic wastewater
and activated sludge, it may be subject to biodegradation in natural waters. Since DBahA's
absorbs solar radiation strongly, it may be subject to direct photolysis in natural waters; however,
the photosensitivity of polyaromatic hydrocarbons is strongly dependent upon the nature of the
surface upon which the compound is adsorbed.
ATMOSPHERIC FATE: Dibenz(a,h)anthracene (DBahA) released to the atmosphere will likely
be associated with particulate matter and may be subject to moderately long range transport,
depending mainly on the particle size distribution and climactic conditions which will determine
the rates of wet and dry deposition. Its presence in areas remote from primary sources
demonstrates the potential for this long range transport as well as DBahA's considerable stability
in the air. The estimated vapor phase half-life in the atmosphere is 1.00 day as a result of reaction
with photochemically produced hydroxyl radicals.
|
|---|
| Drinking Water Impact | DRINKING WATER: Identified, not quantified, in finished drinking water .
EFFL: USA Nationwide Urban Runoff Program, not detected in 86 samples from 15 cities .
Coal coking wastewaters, plant A (plant B) final effluent from biological oxidation process
discharged to river, 0.062-0.23 ppb (0.017- 0.08 ppb), suspended solid, 2.0-2.9 ppb (0.06-0.5
ppb) . Gasoline engine exhaust, 96 ug/g, coke oven, 84-124 ug/g sample . Combined
o-Phenylene pyrene and dibenz(a,c and/or a,h)anthracene: effluent channel from a coking plant,
water, 0.95 ppb, sediment, 8.6 ppm dry wt .
|
|---|
