The CSF values (upper 95% CI estimate of initial dose–response curve) for continuous inhalation exposure
to B[a]P obtained from several data sets (respiratory tract tumors in hamsters and gastric tumors in mice) by Collins et al. (1991) range between 1.3–16.9(m g kg1 day1)1 of B[a]P. The differences are due in part to the different treatment procedures and to assumptions adopted on animal physiological parameters
(e.g., surface area scaling factor). Ingestion exposure data were used for inhalation exposure
assessment by considering the intake dose with route to-route extrapolation.