International Agency for Research on Cancer (IARC) - Summaries & Evaluations
CHLORODIFLUOROMETHANE
VOL.: 41 (1986) (p. 237)
CAS No.: 75-45-6
5. Summary of Data Reported and Evaluation
5.1 Exposure data
Chlorodifluoromethane is produced extensively for use in refrigeration
and air conditioning; significant quantities are subsequently released
into the atmosphere, resulting in widespread, low-level human
exposure. Occupational exposure to chlorodifluoromethane occurs during
its production and use.
5.2 Experimental data
Chlorodifluoromethane was tested for carcinogenicity in one experiment
in rats by oral administration by gavage and in experiments in rats
and mice by inhalation exposure. No increase in tumour incidence was
observed in rats after oral administration. The inhalation study in
mice was inconclusive for males, and negative results were obtained
for females. In the inhalation study in rats, males receiving the high
dose had increased incidences of fibrosarcomas and Zymbal-gland
tumours; negative results were obtained for female rats.
Chlorodifluoromethane causes malformations of the eyes of fetal rats,
but has no reproductive effect in male rats and does not cause
prenatal toxicity in rabbits following exposure by inhalation.
Chlorodifluoromethane is mutagenic to Salmonella typhimurium in the
presence and absence of an exogenous metabolic system. It does not
induce mutation or gene conversion in yeast, or DNA damage or mutation
in cultured mammalian cells. It does not induce chromosomal damage in
bone marrow or dominant lethal mutations in mice or rats treated in
vivo.
5.3 Human data
No data were available to evaluate the reproductive effects or
prenatal toxicity of chlorodifluoromethane to humans.
A small study of workers exposed to a mixture of chlorofluorocarbons,
including chlorodifluoromethane, was uninformative with regard to the
carcinogenic hazard of this chemical.
5.4 Evaluation
There is limited evidence for the carcinogenicity of
chlorodifluoromethane to experimental animals.
There is inadequate evidence for the carcinogenicity of
chlorodifluoromethane to humans.
For definition of the italicized terms, see Preamble Evaluation.
Subsequent evaluations: Suppl. 7 (1987); Vol. 71 (1999)
Synonyms
- Algeon 22
- Algofrene 22
- Algofrene Type 6
- Arcton 4
- Arcton 22
- CFC 22
- Daiflon 22
- Difluorochloromethane
- Difluoromonochloromethane
- Dymel 22
- Electro-CF 22
- F 22
- FC 22
- Flugene 22
- Forane 22
- Freon 22
- Frigen 22
- Genetron 22
- Haltron 22
- Isceon 22
- Isotron 22
- Khaladon 22
- Monochlorodifluoromethane
- R 22
- Ucon 22
Last updated: 13 April 1999