PBAT is currently a key component in our range of compostable packaging. While PBAT is easily biodegradable and will decompose in home compost leaving no toxic residues, it is currently partly derived from petrochemicals, yip, oil. This means it's not renewable (because the earth's oil stocks are finite and becoming depleted) and this is why we're working super-hard to research and test some of the emerging resins which have a higher bio-base (ie. are more made from plants). Interestingly, it is PBAT that is added to make the product degrade quickly enough to meet the home compostability criteria.