Biodegradable plastic will degrade as a result of bacterial activity. In order to be classified compostable, the degradation must meet certain specified criteria such as rate biodegradation, maximum residue of material left at a specific point in time and a requirement for the material to have no harmful impact on the final compost or the composting process. All compostable plastic is therefore also biodegradable. The standard for compostable plastic used is the European standard EN-13432.
Degradable plastics are not compostable. Most of the products using the labelDegradable plastic, degrade as result of physical and chemical impact (fracture into smaller pieces of plastic). They are oil based products with special additives that assist their ‘fragmentation’. Biological activity is not a significant part of the degradation of these products, or the process is too slow to earn the classification Biodegradable orCompostable (the biological degradation will typically take many years).
Bags like these claiming to be 100% degradable cannot be used in your green wheelie bin as they are not compostable. Try to avoid using these bags if possible, by using a re-usable bag when shopping. They can be recycled at certain ‘plastic bag’ recycling collection points (found at some supermarkets), or use them as bin liners for you landfill rubbish, instead of buying black bin liners.