When pregnant with dd I questioned this too... I just felt better with glass, especially since we don't use plastic in our house.. all of our food storage containers are glass, all my drinking bottles are glass ... in the end I settled with glass and SOOOOOOOOO glad I did.. I love love love them!!! I've even dropped one on the tile before but it was perfectly fine!!! I am very careful generally and never gave one to dd for herself to hold.. I was going to get some silicon sleeves for them but didn't need to!!! I can even safely run them through the dishwasher and not feel bad about the chemicals being heated up in there.. I did buy some awesome glass zippy cups with super thick silicone sleeves and those are awesome!!!