What is the difference between degradable, biodegradable and compostable disposable nappies?
Don’t get sucked into greenwashing, look for the compostable standards.
The term biodegradable is the chemical process in which materials are transformed into natural substances such as water, carbon and biomass with the help of microorganisms. Everything is biodegradable to some degree, eventually. But in Australia there are no regulations around the term ‘bio’ so the product may break down quicker than a ‘degradable’ one, but it still breaks down into tiny pieces of plastic that may never dissolve or disappear completely. So when you see the term ‘biodegradable’ the product or packaging doesn’t have to comply with any type of criteria. 
Compostable products are made from plant based materials.
For products or packaging to be called compostable it has to biologically decompose and disintegrate in a composting system (under either commercial or home composting conditions) to set levels within a defined period of time. The compost must also meet specific quality criteria.
The majority of landfills will not compost waste.
- For Commercial composting it should say certified to Australian Standard AS4736 (Biodegradable plastics- Biodegradable plastics suitable for composting and other microbial treatment). A certified compostable product will have the leaf symbol on it, with the standard.
- For Home composting it should say certified to Australian Standard AS 5810-2010 (Biodegradable plastics- Biodegradable plastics suitable for home composting).
- BS EN 13432/ EN 13432:2000 (Packaging. Requirements for packaging recoverable through composting and biodegradation. Test scheme and evaluation criteria for the final acceptance of packaging).
Currently NZ doesn’t have a specific compostable standard of their own, but some companies are adopting international standards, look for industrial vs home compostable standards and whether you have access to industrial compostable facilities.