Pyrene (Benzo(def)phenanthrene) Cas No. 129-00-0

Pyrene

(Benzo(def)phenanthrene)

Cas No. 129-00-0

Potential sources and exposure

Pyrene is a PAH. The reader should refer to the general profile on PAHs for

exposure information.

Physical and chemical properties

Property

Value

Molecular weight

202.2 g/mol

2.5 10-6 at 25 oC

Vapor pressure

0.135 mg/L at 25 oC

Water solubility

Koc

38,000 mL/g

log Kow

4.88

5.1 10-6 atm-m3/mol at 25 oC

Henry's Law Constant

Toxicity

Pyrene is considered to be a skin irritant in humans (as cited in IRIS 1992).

Pyrene has produced negative results in most mutagenicity assays (USEPA

1982). IARC (1983) concluded that there is limited evidence that pyrene is

active in short-term mutagenicity assays. Pyrene is classified as a Group D

carcinogen by the USEPA based on the lack of human carcinogenicity data and

inadequate data from animal bioassays.

The RfD for oral exposure to pyrene is 0.03 mg/kg-day, based on the

observation of kidney toxicity in mice that received subchronic dosing with

pyrene by gavage (USEPA 1989 as cited in IRIS 1992). Confidence in the

database is low due to the lack of supporting evidence from other subchronic,

chronic, or developmental/reproductive studies.

Toxicokinetics

Human exposure to pyrene is almost exclusively through ingestion and

inhalation although it can be absorbed through the skin. There are no

pharmacokinetic data for pyrene in humans (USEPA 1980). Because of their

high lipid solubility, PAHs are believed to be distributed throughout the body.

Relative to other tissues, they tend to localize in body fat and fatty tissues.

Pyrene, like other PAHs, is apparently metabolized via the microsomal mixed

function oxidase system in mammals.

D68

Appendix D Toxicological Profiles