Safety of talc - the FDA have a report at www.fda.gov/Cosmetics/ProductsIngredients/Ingredients/ucm293184.htm
They analysed samples from four bulk cosmetic talc suppliers, looking for asbestos contamination, and found none in any of them. (but five other suppliers did not comply with their request for samples)
Apparently the reason there was some concern was because talc is a silicate (Chemically, talc is a hydrous magnesium silicate with a chemical formula of Mg3Si4O10(OH)2.) and "Asbestos is also a naturally occurring silicate mineral, but with a different crystal structure. Both talc and asbestos are naturally occurring minerals that may be found in close proximity in the earth. Unlike talc, however, asbestos is a known carcinogen. For this reason, FDA considers it unacceptable for cosmetic talc to be contaminated with asbestos."
The link has a list of suppliers and (more usefully for the public) brands and products containing talc with no asbestos found. Johnson's Baby Powder is on the list.