The Australian Organics Recycling Association (AORA) and the Australian Bioplastics Association (ABA) have published a joint position paper on Certified Compostable Bioplastics.

AORA  supports the use of compostable bags and plastics which meet the requirements of AS 4736 and AS 5810 as verified by the Australasian Bioplastics Association allows for safe, effective source separation acceptable for organic resource processing/recycling. Conventional plastics such as polyethylene are not certified compostable and are not biodegradable in any context. Varieties of polyethylene containing additives, such as those called oxo-degradable or oxo-biodegradable are not certified compostable and are not suitable for normal organic processing/recycling operations as they are not biodegradable.

See Joint Position Paper here