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CARBON TETRACHLORIDE
CAS No: 56-23-5
I. PHYSICAL AND CHEMICAL PROPERTIES (From HSDB (1998) except as noted)
Molecular weight 153.8
Boiling point
76.7°C
Melting point
-23°C
Vapor pressure 91.3 mm Hg @ 20°C
Air concentration conversion 1 ppm = 6.3 mg/m 3 @ 25°C
II.
HEALTH ASSESSMENT VALUES
Unit Risk Factor: 4.2 E-5 (µg/m 3 ) -1
Slope Factor: 1.5 E-1 (mg/kg-day) -1
[Calculated from mouse liver tumor incidence data (Edwards et al., 1942) using a linearized
multistage procedure, extra risk (US EPA, 1984); revised by CDHS (1987).]
III.
CARCINOGENIC EFFECTS
Human Studies
Capurro (1979) reported a study on the residents in a rural valley polluted by vapors from a solvent
recovery plant for at least 10 years. Chloroform, benzene, methyl isobutyl ketone, trichloroethylene and
26 other organic agents were detected in the air in addition to carbon tetrachloride (Capurro, 1973).
The author reported four excess cases of lymphoma. Attributing these cancer cases to carbon
tetrachloride alone would be inappropriate due to exposure to the other contaminants.
In a preliminary study of 330 laundry and dry cleaning workers, Blair et al. (1979) examined
occupational exposure to carbon tetrachloride and other dry cleaning agents. Information from death
certificates indicated an excess of deaths from lung, cervical and liver cancer, and leukemia. Katz and
Jowett (1981) studied female laundry and dry cleaning workers in Wisconsin. Their results failed to
show an overall increase in malignant neoplasms, but they did report an elevated risk for cancers of the
kidney and genitals (unspecified), along with smaller excesses of bladder and skin cancer and
lymphosarcoma. However, the use of carbon tetrachloride has been of only minor importance in dry
cleaning since the 1950’s and quantitative data on exposure to carbon tetrachloride were not presented
in these studies.
Hernberg et al. (1984) reported a case-control study on primary liver cancer and exposure to solvents.
Of 126 cases, two had a history of exposure to carbon tetrachloride, among other solvents. They
concluded that there was an association between primary liver cancer and exposure to “solvent” among
women, but not for men.
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