Biodegradable plastic
Biodegradable simply means the material can break down into natural substances like water and carbon dioxide. Some types are made from plants, others from traditional plastics with added ingredients to help them along.
The catch is that biodegradable plastics need certain conditions (light, oxygen and warmth) to break down properly. Those conditions don’t usually exist in landfill, so the process can take years. Even then, they may release methane, a powerful greenhouse gas.
Compostable plastic
Compostable plastics sound like the dream alternative, but they also come with conditions. These products are designed to break down fully into safe, usable compost — but only in the right environment. Most need the carefully managed conditions of an industrial composting facility.
If you put them into a backyard compost heap and you’ll probably still see them months later. If you want to be sure, look for certification to the Australian standards: AS 4736 (for commercial composting) or AS 5810 (for home composting).
What goes where?
Neither biodegradable nor compostable plastics should go into your household recycling bin. They can’t be recycled with other plastics and may contaminate the whole load. Certified compostable items can usually go into food and garden organics bins if your council provides them, although it’s a good idea to check with your local council. If that’s not available, they need to go into general waste.
