In a recent announcement, the World Health Organization's International Agency for Research on Cancer (IARC) classified talc as "probably carcinogenic" for humans. The decision was based on limited evidence suggesting a potential link between talc and ovarian cancer in humans, as well as strong evidence of its carcinogenic effects in rat studies and human cell research.

Talc, a naturally occurring mineral mined in various parts of the world, is commonly used in products such as talcum baby powder and cosmetics. According to the Lyon-based IARC, most people are exposed to talc through the use of these products. However, the agency highlighted that the most significant exposure occurs during the mining, processing, and manufacturing stages.

The IARC referenced several studies showing an increased rate of ovarian cancer in women who use talc on their genitals. However, it also noted the potential for contamination with cancer-causing asbestos in some of these studies, which prevents the establishment of a definitive causal relationship.

While the classification by the IARC raises concerns about the potential health risks associated with talc, experts caution against misconstruing the announcement as a "smoking gun." Kevin McConway, a statistician at the UK's Open University, emphasized that the observational nature of the studies means they cannot conclusively prove causation. He stated that there is no definitive evidence that talc use directly increases the risk of cancer.

This classification coincides with Johnson & Johnson's decision last year to remove its baby powder from the North American market due to increased scrutiny surrounding talc and cancer. The company recently agreed to a $700 million settlement to resolve allegations of misleading customers about the safety of its talcum-based powder products. It is important to note that Johnson & Johnson did not admit any wrongdoing as part of the settlement.

In addition to the talc classification, the IARC also categorized acrylonitrile, a chemical used in polymer production, as "carcinogenic to humans." The agency highlighted the sufficient evidence linking acrylonitrile to lung cancer, given its use in a wide range of consumer products such as clothes, carpets, and plastics.

As concerns about the potential health risks associated with these substances persist, further research and regulations may be necessary to ensure the safety of talc-based products for consumers. It is crucial to note that the IARC's classification is aimed at identifying the potential for cancer-causing properties and does not provide definitive proof of causation.

The details of the IARC's findings can be found in their publication in The Lancet Oncology.