How are PET bottles sustainable?

Question

How are PET bottles sustainable?

Answer 1

They aren't.  However, they are lightweight and can be recycled.

Answer 2

They are re-cycleable in some areas. They are not turned back into PET bottles, adn most plastics tend to NOT be made back into food containers.

If you want to be more sustainable, try to avoid plastics and containers or packaging like this.  

Metal containers are a bit better, Glass a bit better still.