International Agency for Research on Cancer (IARC) - Summaries & Evaluations

(Group 2B)

For definition of Groups, see Preamble Evaluation.

VOL.: 71 (1999) (p. 479)

CAS No.: 96-12-8
Chem. Abstr. Name: 1,2-Dibromo-3-chloropropane

5. Summary of Data Reported and Evaluation

5.1 Exposure data

Exposure to 1,2-dibromo-3-chloropropane has occurred during its production and use as a pesticide, nematocide and soil fumigant; however, production is believed to have ceased. It has been detected at low levels in ambient air, water and soil.

5.2 Human carcinogenicity data

Four cohort studies and one population-based case–control study have examined the risk of cancer among populations exposed to 1,2-dibromo-3-chloropropane, among other chemicals. In two of the cohort studies, an excess of lung cancer was observed based on small numbers of cases. In a third cohort study, an excess of liver and biliary tract cancers was found, while in the fourth an excess of cervical cancer and a non-significant excess of melanoma and leukaemia were observed. However, in both of the last two studies, it was unclear what proportion of the population was exposed to 1,2-dibromo-3-chloropropane, and there was exposure to multiple pesticides. In the case–control study, there was a non-significant association of gastric cancer and leukaemia with exposure to 1,2-dibromo-3-chloropropane in groundwater.

5.3 Animal carcinogenicity data

1,2-Dibromo-3-chloropropane has been tested by oral administration and inhalation in mice and rats. After oral administration, it produced squamous-cell carcinomas of the forestomach in animals of each species and adenocarcinomas of the mammary gland in female rats. After inhalation, it induced nasal cavity and lung tumours in mice, and nasal cavity and tongue tumours in rats of each sex and pharynx in females. In fish, an increased incidence of liver tumours was found.

5.4 Other relevant data

1,2-Dibromo-3-chloropropane is metabolically activated via cytochrome P450-catalysed oxidation and glutathione conjugation to form several protein- and DNA-binding products in the rat and mouse. It is also activated in human testicular cells in vitro. It disturbs spermatogenesis and has caused male infertility in humans. 1,2-Dibromo-3-chloropropane is a bacterial mutagen in the presence of metabolic activation. It causes DNA damage and genotoxicity in animal cells in vitro and in vivo.

5.5 Evaluation

There is inadequate evidence in humans for the carcinogenicity of 1,2-dibromo-3-chloropropane.

There is sufficient evidence in experimental animals for the carcinogenicity of 1,2-dibromo-3-chloropropane.

Overall evaluation

1,2-Dibromo-3-chloropropane is possibly carcinogenic to humans (Group 2B).

For definition of the italicized terms, see Preamble Evaluation.

Previous evaluations: Vol. 15 (1977); Vol. 20 (1979); Suppl. 7 (1987)


Last updated: 12 April 1999

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