Yes, dishes made from window glass are safe to serve food on. Since glass is a non-porous material, it does not interact with food, unlike other materials (plastic, Styrofoam).  Lead is not an ingredient used in the production of window glass. You may have heard of “lead crystal”. It refers to fine crystal (goblets, decanters, crystals) where (in the past) lead was added to make it perfectly pigment-free. In my pieces, you will actually see the natural, aqua-green/blue tint of glass because lead was not added. (see the question above)