You might have heard that sure, parabens and other chemicals are bad if ingested, but they can't penetrate your skin so you don't have anything to worry about. The fact is, that much of what we place on our skin is absorbed into our bloodstream. Just think about nicotene and birth control patches. While there may be some chemicals that are too large to enter your bloodstream most are small enough to penetrate. We have had studies done on everything from umbilical cords of unborn children to adult urine and have found alarming levels of cosmetic chemicals. So I say you're better off doing your best to avoid all known harmful chemicals because chances are they're entering your bloodstream.