home edit2 whole TSD November 2002 PDF format - OEHHA

DAB/day by gavage for the life of the animals. All doses induced the formation of liver tumors;
the induction time was inversely proportional to the dose, ranging from 34 days (30 mg/day) to 700
days (1 mg/day). For exposure groups in the 3-30 mg/day range, the total carcinogenic dose was
about 1000 mg. Daily exposures of 0.1 or 0.3 mg/rat did not induce tumors.
Druckrey (1967) exposed rats to 5 mg DAB/rat by gavage for 40, 60, 100, 140 or 200 days, then
observed the animals for the remainder of their lifespan. Percent incidences of liver carcinomas were
20, 26, 49, 80 and 81, respectively.
IV.
DERIVATION OF CANCER POTENCY
Basis for Cancer Potency
The feeding study by Kirby and Peacock (1947) conducted in Wistar-derived albino rats is listed in
Gold et al. (1984). Cancer potency is based on liver tumors in the female rats.
Methodology
Expedited Proposition 65 methodology (with cross-route extrapolation) was used to derive a cancer
potency factor. A unit risk factor was then calculated by OEHHA/ATES from the cancer potency
factor using a reference human body weight of 70 kg and an inspiration rate of 20 m 3 /day.
V. REFERENCES
California Environmental Protection Agency (Cal/EPA) 1992. Expedited Cancer Potency Values and
Proposed Regulatory Levels for Certain Proposition 65 Carcinogens. Office of Environmental Health
Hazard Assessment, Reproductive and Cancer Hazard Assessment Section, Berkeley, CA.
Druckrey H. 1967. Quantitative aspects in chemical carcinogenesis. In:. UICC Monograph Series, No.
7. Truhaut R., ed., Springer-Verlag, Berlin, Germany, pp. 60-78.
Druckrey H and Küpfmüller K. 1948. Quantitative Analyse der Krebsentstehung Z Naturforsch [C]
3b:254-266.
Gold L, Sawyer C, Magaw R, Backman G, de Veciana M, Levinson R, Hooper N, Havender W,
Bernstein L, Peto R, Pike M and Ames B. 1984. A Carcinogenic Potency Database of the
standardized results of animal bioassays. Environ Health Perspect 58:9-319.
Hazardous Substance Data Bank (HSDB) 1994. National Library of Medicine, Bethesda MD (CD-
ROM Version). Micromedix, Inc., Denver CO, Edition 22.
262