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MICHLER'S KETONE (4,4 / -BIS(DIMETHYLAMINO) BENZOPHENONE)
CAS No: 90-94-8
I. PHYSICAL AND CHEMICAL PROPERTIES (From HSDB, 1994)
Molecular weight 268.35
Boiling point
>360 °C (with decomposition)
Melting point 172 °C
Vapor pressure
not available
Air concentration conversion 1 ppm = 10.98 mg/m 3
II.
HEALTH ASSESSMENT VALUES
Unit Risk Factor: 2.5 E-4 (µg/m 3 ) -1
Slope Factor: 8.6 E-1 (mg/kg-day) -1
[ Female rat liver tumor data (NCI, 1979), contained in Gold et al. (1984) database, expedited
Proposition 65 methodology (Cal/EPA, 1992), with cross-route extrapolation.]
III.
CARCINOGENIC EFFECTS
Human Studies
No studies on the potential carcinogenic effects of Michler’s ketone in humans are known to exist.
Animal Studies
Male and female Fischer 344 (F344) rats and B6C3F 1 mice were fed diets containing Michler’s ketone
(NCI, 1979). Mice were fed diets containing 1250 or 2500 mg/kg diet Michler’s ketone for 78 weeks;
animals were then maintained on control diet for an additional 13 weeks. Rats were fed diets containing
250 or 500 mg/kg diet Michler’s ketone for males, 500 or 1000 mg/kg diet for females; the treatment
period for both sexes was 78 weeks. The treatment period was followed by an observation period; 28
weeks for male rats and high dose female rats and 29 weeks for low dose female rats. Treatment group
sizes were 50 animals/sex/species/group; control group sizes were 20 animals/sex/species.
Significant dose-related increases in incidences of liver tumors (hepatocellular adenomas and
carcinomas) were observed in rats and female mice, and of hemangiosarcomas in male mice. Tumor
incidence data is listed in Table 1.
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