Talcum powder is a cosmetic product made from finely ground talc, an extremely soft mineral. One of its most common uses is in baby care, with some parents using it to reduce rashes and irritation from diapers. It can also be used on adults to prevent chafing and rashes, and some people have come up for creative uses for this product, like sweeping it into the cracks of wooden floors to prevent them from squeaking.
This product's primary role is as a moisture absorber. By sucking up moisture from the surrounding area, talcum powder keeps the skin dry. This can reduce the risk of rashes and chafing from sweat, urine, and other bodily secretions, and it also increases comfort in hot weather. Many babies find it very comforting, since they do not have any control over when their diapers are changed.
Women sometimes use talcum powder to avoid chafing between the thighs while wearing skirts, and athletes may also apply it before suiting up for sports to help wick away sweat and increase comfort. It is also used on some bed-bound people to prevent the development of rashes and sores, especially if they have thick folds of skin which could harbor moisture.
Some people have raised concerns that talcum products may be linked with cancer, often in strongly-worded scare campaigns which are designed to frighten consumers into stop using it altogether. The American Cancer Society has conducted several studies to determine whether or not talcum powder is linked with cancer, and the results have been inconclusive.
Inhaling or swallowing this product can certainly be harmful, as it can irritate the lungs and intestinal tract. Exposure to this product has also caused the development of tumors in some laboratory animals. However, studies on humans have not been able to prove a positive link, partially because some study subjects were exposed to talcum powder which contained asbestos; until the 1970s, it was perfectly legal to have asbestos (a naturally occurring mineral) in talcum products. Further studies are needed to determine whether or not it is totally safe.
For people who are concerned that talcum powder could be harmful, there are talc-free products with a similar function on the market. Most of these products are made with cornstarch, and in fact some people just use straight cornstarch, skipping the perfumed and ornately packaged version in the natural baby products aisle.