Meet The Safe Sippy? stainless steel drinking cup ? one small step in creating a less toxic world for our children. The Safe Sippy? cup breaks away from the all-plastic sippy cup designs of the past. From the clean, non-leaching stainless steel cup to the unique safety features to the plastics free of Bisphenol A and other harmful chemicals, The Safe Sippy? cup was created to accomplish one simple goal: Clean In, Clean Out. Direct from Safe Sippy.... We thought carefully about every feature while we were designing our cup. The most important issue of all was safety. So it?s not surprising that the first thing people ask us is, ?How come the cap is plastic?? The answer is simple: No child (or adult, for that matter) wants to suck on a stainless steel straw. It hurts our teeth just thinking about it. We did the next best thing. We kept contact between water and plastic to a minimum, and we insisted that all our plastics be certified free of Bisphenol A, phthalates and DEHA. We pay for extensive independent laboratory testing on our cups to make sure they are free of these chemicals. Lastly, we make our cap out of Polypropylene, #5 plastic. PP is the most stable of all plastics. We also took into consideration the fun stuff, like hands - little hands, messy hands, hands that can't quite hold onto big things yet; the developing mouths and speech abilities of growing infants; children's desire to look at bright, colorful objects; children's propensity for turning food delivery systems into projectiles...and other stuff as well.