There is a lot of confusion between a few plastics terms that define how easily they ‘return to nature’. Below, we try to explain the difference between some of them:
Degradable – means it can be degraded, broken down. Cutting plastic with scissors, grinding into dust is degrading it. You may have seen flexible plastics that become brittle and break down in the sun and crumbles. Degradable plastics just become smaller and smaller pieces of plastic. It is small pieces of plastic like this that fish can feed on, filling their intestines, but giving them no nutrition.
Biodegradable – Biodegradable plastics are degradable AND can be broken down by micro-organisms into other organic molecules that can become part of a living organism.
Compostable – Compostable plastics are biodegradable AND they will degrade relatively quickly.
Bioplastics – are made from natural materials like vegetable oils, not fossil fuels. Depending on how they are processed bio plastics may be compostable, biodegradable or just degradable.
Oxo-degradable plastics - are plastics that will break up into small pieces more quickly than regular plastics, still leaving small pieces of plastic behind.
Take note that the majority of tests for bio-degradability specify how to test and not a pass / fail criteria, so watch out for claims that a plastic passes one test or another!