Baby powder is usually a mixture of talcum, corn starch and perfumes. The composition will differ based on the type of baby powder.

There are purely talcum based baby powders, and there are pure corn starch based baby powders. For those who are interested in the chemical composition
of talcum, the formula may be either Mg3Si4O10(OH)2 or 3MgO.4SiO2.HOH, depending on the type of ingredients used. Does it really matter? I guess at least a few of you want to know what you have been putting on your baby’s bottom. Well, at least, it won’t harm you!