We changed some months ago the plastic sippy cup that Stella had against one made of stainless steel. The cup was in principle without Bisphenol A (BPA), but new research provide evidence that BPA-free plastic products also leach synthetic estrogen, which especially harms the health of infants and children. Stella now has a pretty mug made of stainless steel by foogo. We also use glass baby bottles (we have some baby bottles made of plastic as she can hold them without the danger of breaking, but it gives me the creeps…). Have a look at my post about the throw-away society referring to PET-bottles.