Toxicity Profiles

RAGs A Format for Benzo[k]fluoranthene - CAS Number 207089

Benzo[k]fluoranthene is a polycyclic aromatic hydrocarbon (PAH) with one five-membered and four six-membered carbon rings. It is a crystalline solid. Benzo[k]fluoranthene is insoluble in water but is soluble in acetic acid, benzene, and ethanol. No commercial production or commercial use of benzo[k]fluoranthene is known at this time, however, small amounts of this compound are used for research. Benzo[k]fluoranthene is found in fossil fuels and occurs ubiquitously in products of incomplete combustion. It has been detected in mainstream cigarette smoke, gasoline engine exhaust, emissions from burning coal and from oil-fired heating, lubricating oils, used motor oils, crude oils, and in soils, surface waters, and groundwater at hazardous waste sites.

No absorption or excretion data were available for benzo[k]fluoranthene; however, by analogy to structurally-related PAHs, primarily benzo[a]pyrene, it would be expected to be absorbed from the gastrointestinal tract, lungs, and skin. No data were found concerning the acute, subchronic, chronic, developmental, or reproductive toxicity of benzo[k]fluoranthene in humans.

No long-term oral or inhalation bioassays were available to assess the carcinogenicity of benzo[k]fluoranthene in humans. Benzo[k]fluoranthene was tested for carcinogenicity in animals in dermal application, subcutaneous (s.c.) injection, lung implantation, and intraperitoneal (i.p.) injection studies. Dermal applications of 0.5% solutions of benzo[k]fluoranthene for life produced only a few skin papillomas in mice, but in initiation-promotion assays, benzo[k]fluoranthene was active as an initiator of skin carcinogenesis. Injection site sarcomas developed in mice given three s.c. injections of 0.6 mg benzo[k]fluoranthene and dose-related increases of epidermoid carcinomas of the lungs were reported in rats receiving single lung implants of 0.16-4.15 mg benzo[k]fluoranthene. In a short-term assay, hepatic and lung tumors occurred in newborn mice receiving 2.1 umol benzo[k]fluoranthene via i.p. injection.

Based on no human data and sufficient evidence for carcinogenicity in animals, EPA has assigned a weight-of-evidence classification of B2, probable human carcinogen, to benzo[k]fluoranthene.

The following is a presentation of the toxicity information associated with Benzo[k]fluoranthene:

• The Oral Slope Factor is 7.30E-02 (mg/kg-day)^-1.
• The Inhalation Unit Risk is 8.8E-03 (mg/m³)^-1.
• The Dermal Slope Factor is 2.35E-01 (mg/kg-day)^-1.
• The Dermal Slope Factor is based on a gastrointestinal absorption factor of 0.3100.