PET (PolyEthylene Terephthalate) is a strong but lightweight form of clear polyester. It is used to make containers for soft drinks, juices, alcoholic drinks, water, edible oils, household cleaners, and other food and non-food applications. Being a polymer, polyethylene terephthalate's molecules consist of long chains of repeating units only containing the carbon (C), oxygen (O) and hydrogen (H) organic elements.