Dibenzo(a,h)Anthracene (1,2,5,6-Dibenzanthracene, Dibenz(a,h)anthracene) Cas No. 53-70-3

Dibenzo(a,h)Anthracene

(1,2,5,6-Dibenzanthracene, Dibenz(a,h)anthracene)

Cas No. 53-70-3

Potential sources and exposure

Dibenzo(a,h)anthracene is a PAH. The reader is referred to the general profile

on PAHs for exposure information.

Physical and chemical properties

Value

Property

Molecular weight

278.36 g/mol

5.0 10-4 mg/L at 25 oC

Water solubility

1.0 10-10 mm Hg at 20 oC

Vapor pressure

3.3 10 6 mL/g

Koc

log Kow

6.8

7.30 x 10-8 atm-m3/mol

Henry's Law Constant

Toxicity

Although there are no human data that specifically link exposure to

dibenzo[a,h]anthracene with human cancers, dibenzo[a]anthracene is a

component of mixtures that have been associated with human cancer. These

include coal tar, soots, coke oven emissions, and cigarette smoke (USEPA 1984,

IARC 1983).

Dibenzo(a,h)anthracene [DB(a,h)A] has been tested for carcinogenicity in a

variety of test species employing a number of different routes of exposure with

positive results having been reported in the majority of studies. Little data were

identified concerning toxic effects other than tumor induction in the various test

species. USEPA has classified dibenzo(a)anthracene as group B2; probable

human carcinogen, based on sufficient data from animal bioassays.

Dibenzo[a,h]anthracene produced carcinomas in mice following oral or dermal

exposure and injection site tumors in several species following subcutaneous or

intramuscular administration. Dibenzo[a,h]anthracene and some of its

metabolites have induced DNA damage and gene mutations in bacteria as well as

gene mutations and transformation in several types of mammalian cell cultures.

Toxicokinetics

Like other PAH compounds, DB(a,h)A is oxidized by liver enzymes to form

water-soluble derivatives that can be excreted in urine. No information is

available regarding dermal or oral absorption coefficients.

No quantitative data were located concerning the absorption of DB(a,h)A in

experimental animals. The 5,6-oxide and the 1,2- 3,4- and 5,6-dihydrodiols have

been detected as metabolites of DB(a,h)A after incubation in rat liver

D32

Appendix D Toxicological Profiles