If you have a baby, whether you breast feed or use infant formula, you will probably use a baby bottle at some point. And probably quite a few baby bottles. If you have a toddler, “sippy cups”–those no-spill cups with lids and a spout–are de rigueur to avoid disasters. But some scientists suspect that the material commonly used for baby bottles and some sippy cups, polycarbonate plastic, could be harmful to your baby’s health.