Plastic is lighter and easier to transport than glass. There are different varieties of plastic, although the best ones are those that are BPA-free (chemical compound) and are a good choice as a resistant bottle for children. Glass is a more fragile and heavier material, but is more environmentally friendly than plastic. Stainless steel keeps liquids hot or cold much longer than plastic or glass. If you are looking for a more sustainable option, we recommend glass or stainless steel for your eco-friendly bottles