International Agency for Research on Cancer (IARC) - Summaries & Evaluations
VOL.: 42 (1987) (p. 185)
5. Summary of Data Reported and Evaluation
5.1 Exposure data
Talc occurs in various geological settings around the world but
is usually formed by alteration of ultramafic rocks or dolomites.
Talc deposits may contain various other minerals, including
carbonates, free silica and serpentines (including chrysotile) and
amphibole minerals (asbestiform and nonasbestiform). Occupational
exposures occur during mining, milling, processing and in a wide
variety of secondary industries (e.g., ceramics, paper, rubber and
paint production). Exposure of the general population occurs through
use of products such as cosmetics.
5.2 Experimental data
Talc of different grades was tested for carcinogenicity in mice
by subcutaneous, intraperitoneal and intrathoracic injection, in rats
by oral administration, inhalation exposure and intraperitoneal,
intrathoracic and intrapleural injection, and in hamsters by
inhalation exposure and intratracheal instillation. The majority of
these studies were inadequate. Tumour incidence was not increased
following either the administration of single doses of various talcs
to rats by intrapleural administration or administration of talc by
four intraperitoneal injections. A single subcutaneous injection of
talc in mice did not produce local tumours. No tumour was produced by
administration of talc in the diet of rats. In most of the above
studies, characterization of the talc was insufficient to determine
whether it contained asbestiform fibres.
No teratogenic effect was observed in rats, mice, hamsters or
rabbits following oral administration of talc.
Talc was not mutagenic to Salmonella typhimurium or Saccharomyces
cerevisiae. It did not induce chromosomal aberrations in cultured
human cells or in rats in vivo or dominant lethal mutations in rats.
5.3 Human data
Case reports have suggested an association between exposure to
talc containing asbestiform fibres and mesothelioma.
Proportionate mortality studies of miners and millers of talc
containing asbestiform tremolite and anthophyllite showed an excess of
lung cancer and one case of mesothelioma. A cohort study of workers
in one company revealed significant excess mortality from lung cancer
and from nonmalignant respiratory disease. Mortality from lung cancer
increased with latency.
In several mortality studies, cancer risk was assessed among
miners and millers of talc that was reported to contain no more than
trace amounts of asbestiform minerals. A cohort mortality study of
talc miners and millers showed an excess of lung cancer in underground
miners but not in millers; a contributory etiological role of radon
daughters to the lung cancer risk in miners could not be excluded.
Three other studies suffered from methodological limitations and could
not be interpreted.
A case-control study suggested an approximate doubling of the
risk for ovarian cancer among women after perineal use of talc.
There is inadequate evidence for the carcinogenicity of talc to
There is inadequate evidence for the carcinogenicity to humans of
talc not containing asbestiform fibres, while there is sufficient
evidence for the carcinogenicity to humans of talc containing
For definition of the italicized terms, see Preamble Evaluation.
Subsequent evaluation: Suppl. 7 (1987)
Last updated: 23 April 1998