The Food and Drug Administration has just loudly re-endorsed perhaps the oldest truth in science—that the dose makes the poison. Paracelsus, the father of toxicology, told us 500 years ago, “All substances are poison. There is none which is not a poison. The right dose makes the difference between a poison and a remedy.” Even sunlight and water are poisons at high doses. The FDA has just commented on a new study which found no health impact from low doses of bisphenol-A. BPA is a plasticizer often found at low doses in things like foods, children’s milk bottles, and toys. Activists responded by sending out waves of demands to parents that this useful chemical be banned from the shelves. Read more.