The tell-all on talc's cancer risk

The World Health Organisation upgraded the substance to a group 2A carcinogen for cancer of the ovary

- Wong Seng Weng

Have you ever sprinkled talcum powder on your child during nappy change? I know I have and, in all likelihood, so have many of you.

We may have unwittingly sprinkled a probable carcinogen on our kids, so said the World Health Organisation (WHO).

The International Agency for Research on Cancer (IARC), the cancer research arm of the WHO, recently upgraded talc - also known as talcum powder - from a group 2B carcinogen (possibly carcinogenic) to a group 2A carcinogen (probably carcinogenic) for cancer of the ovary on July 5.

Talc is the softest mineral known to man and can be mined from the earth's crust. In scientific jargon, talc is hydrated magnesium silicate.

When ground to a fine powder, talc has useful properties, such as the ability to absorb moisture and odours, as well as reduce friction when skin surfaces come into contact, thereby preventing abrasions. These are properties that make it an ideal substance to be made into body powder and cosmetics.

Indeed, this has been the traditional base constituent of baby powder for generations. Talc-based body powders still sit on the shelves of many retail stores.

Is a group 2A carcinogen very dangerous?

The IARC has a fairly large catalogue of potential carcinogens broken up into five groupings.

The most dangerous category is group 1, classed as "carcinogenic to humans". In decreasing risk-rating, the categories that follow are - group 2A (probably carcinogenic), group 2B (possibly carcinogenic), group 3 (carcinogenicity not classifiable) and group 4 (probably not carcinogenic).

It is useful to bear in mind that the classification is based on the degree of certainty that a particular agent is carcinogenic and not the potency of the agent in triggering cancer.