Polyethylene terephthalat PET or PETE plastic code 1 is made from carbon, hydrogen and oxygen, just like paper.
It is claimed that, just like paper, it can be safely burnt and will only produce carbon dioxide and water leaving no toxic residue.
I came across this nuggets out there in google land and as you know panning in tham thar rivers often finds you only fools gold.
So lets see if I am richer than Midas or talking through my arsk no questions.
Google MSDS followed by the product name ie MSDS Polyethylene terephthalat
This pulls up the Material Safety Data Sheet for PET