Biodegradable, degradable, compostable – a dummy’s guide

The terms degradable, biodegradable and compostable have started to appear on packaging and bags, but these terms are often used incorrectly and leave the consumer confused. Here is a dummy’s guide to understanding what the terms mean:

Biodegradable plastics are bioplastics that degrade, or break down, into harmless substances through the action of naturally occurring micro-organisms.

Compostable plastics are bioplastics which like, biodegradable plastics, degrade through the action of naturally occurring micro-organisms. These plastics can be safely composted together with organic waste to produce compost, a soil improver. Compostable plastics do not hamper the composting process because they disintegrate safely and do not pollute the final compost.

Degradable plastics are sometimes referred to as oxo-degradable plastics and are polyethylene-based but contain a metal additive to promote degradation. Degradation occurs in the form of repeated fragmentation following exposure to UV light or dry heat.