|Chemical Abstract Number (CAS #)||
||EPA Method 8270 |
Link to the National Library of Medicine's Hazardous Substances
Database for more details
on this compound.
|Use|| IN EXPTL MEDICINE TO INDUCE VARIOUS MALIGNANT TUMORS IN
TESTING ANTINEOPLASTIC DRUGS
|Consumption Patterns|| NOT USED COMMERCIALLY IN U.S.
|Apparent Color|| PLATES, LEAFLETS FROM ACETONE & ALC, FAINT GREENISH-YELLOW
|Melting Point|| 122-123 DEG C
|Molecular Weight|| 256.33
|Environmental Impact|| Contrary to many polynuclear aromatic hydrocarbons (PAHs) including
benz(a)anthracenes, there is no evidence that 7,12-dimethylbenz(a)anthracene (DMBA) is
released into the environment as a product of incomplete combustion despite innumerable PAH
monitoring studies. Only two citations of its occurrence in environmental samples could be found,
kale and mineral oil. The data for kale is suspect and the reference citing its occurrence in mineral
oil was a secondary source in which the experimental details could not be scrutinized. If released
into air or water it will be partially associated with particulate matter. In the atmosphere, DMBA
will be subject to photolysis and photooxidation although no rates specifically relating to DMBA
could be found in the literature. The particulate-bound compound may be transported moderate
distances before settling out. In the water, it will sorb strongly to sediment and the unadsorbed
DMBA in surface layers of water will photodegrade. Its slow desorption from sediment and
particulate matter may maintain a low concentration of the chemical for long periods of time.
Based upon physical properties, DMBA should bioconcentrate in fish. In soil, the strongly
adsorbed DMBA will remain in the upper few centimeters of soil. Its fate there is unknown.
|Environmental Fate|| TERRESTRIAL FATE: If spilled on soil, 7,12-dimethylbenzoanthracene will remain in
the surface layers because it is strongly adsorbed (see also Koc). The possibility that it will slowly
biodegrade in soil, as with other polynuclear aromatic hydrocarbons, has not been investigated.
AQUATIC FATE: If 7,12-dimethylbenzanthracene (DMBA) is released to water, it will sorb to
sediment and particulate matter in the water column. It will photodegrade, the extent of which
will depend on the temperature, dissolved oxygen, and the amount of solar radiation received
which is in turn a function of water depth and turbidity. The estimated half-life of the dissolved
compound in natural water from the southeastern U.S. is 6 hr. The photodegradation of DMBA
sorbed to particulate matter has not been investigated. There is a potential that the sorbed
compound will be slowly desorbed, thereby contributing low levels of DMBA for long periods of
ATMOSPHERIC FATE: 7,12-dimethylbenz(a)anthracene (DMBA) released to the atmosphere
will exist in both the free vapor state and adsorbed to particulate matter. Although DMBA will be
subject to photolysis and photooxidation, no studies could be found in the literature dealing with
these processes in the free vapor or when adsorbed to particulate matter. The sorbed material will
most likely be more resistant to photodegradation. As with other polynuclear aromatic
hydrocabons, it may be transported moderate distances, subject to gravitational settling and
scavenging by rain and snow.