In its natural form, some talc may contain asbestos, which is known to cause cancer. However, modern domestic talcum powder does not contain asbestos.
Asbestos free talc, such as that found in modern talcum powder has been suggested to increase the risk of ovarian cancer in women who apply talcum powder regularly in the genital area. Several studies in women have looked at the possible link between talcum powder and ovarian cancer, with mixed findings. Some studies report a slightly increased risk, while others have found no increase. The evidence is insufficient to conclude that use of talcum powder leads to an increased risk of ovarian cancer. It is also unclear how talcum powder might influence the development of ovarian cancer.
In addition, there is no evidence to suggest that talcum powder increases the risk of other types of cancer. Due to this inconclusive research evidence, talcum powder is classified by the International Agency for Research on Cancer (IARC) aspossibly carcinogenic (cancer causing) to humans when applied to the genital area. IARC is a part of the World Health Organisation which convenes international expert working groups to evaluate the evidence of the carcinogenicity of specific exposures.
Further research is needed to determine whether and how talcum powder might increase the risk of ovarian cancer.
When inhaled, talc that contains asbestos can cause cancer. As asbestos is not an ingredient in modern consumer talc products, exposure risk is mainly for employees in industries who may have long term exposure to natural talc fibres. While some studies of talc miners and millers have suggested an increased risk of lung cancer, other studies have found no increase in risk. Occupational exposure studies can be complicated by the fact that talc in its natural form may contain varying amounts of asbestos and other minerals. Additionally, miners may be exposed to other substances that could affect lung cancer risk, such as radon, leading to difficulties in separating the risks that might be associated with talc from other known risk factors for lung cancer.