While I love Sharpies, pretty much because they are awsome, but equally because they allow me to pay for fun things like Disney World (and less fun things like groceries and my mortgage!), my good friends in Sharpie/Papermate's Consumer Affairs department will tell you NOT to draw on your kids with a Sharpie!! They are not medical grade markers and should not be used on skin.
OP, if you would like to know the answer to your question, please call Newell Rubbermaid -Office Products (aka Sharpie) and ask. The consumer affairs reps are wonderful and will be happy to talk to you. I don't have their # off hand, but they are located in Oak Brook IL. You can get the # online as well.