So most plastics are made from oil and most plastics do not biodegrade. See how and why here…

And yet you will find plastics described as

• degradable
• biodegradable
• compostable

What do these terms actually mean when applied to plastic?

Remember that

• Most traditional, oil-based plastics do not biodegrade.
• Biodegradable products break down as the result of the actions of naturally occurring microorganisms, such as fungi or bacteria, over a time.
• Plastic breaks, tears and cracks. It weathers and sunlight makes it brittle, It falls apart – it degrades – but only into smaller pieces of plastic.
• Find out more about the lifecycle of plastic here.

Degradable Plastic

All plastic degrade – i.e. they fall apart into smaller pieces of plastic. BUT when a plastic is described as degradable it could just describe the falling part process  OR it could mean t a degradation initiator has been added to make it fall apart faster.

Degradation Initiators and Bio-Degradable Plastics

But suppose there was a way of making plastic biodegradable? The industry argue that they can do just that by means of chemical additives known as degradation initiators. Very basically, these additives break the long unnatural plastic polymers into shorter recognisable polymers that microbes can attack and digest – or biodegrade (N.B. lots more research need to be done on this. It is by no means proven).

Because the degradation initiators are biologically  based they are sometimes described as biodegradable. So some traditional plastic bags have been labelled biodegradable.

This is  at best confusing if not deliberately misleading. This  is not the same process as natural biodegrading. Unlike truly biodegradable products they don’t always break down into harmless substances and may leave behind a toxic residue.

More so as  there are some compostable plastics which are also described (correctly) as  biodegradable which do actually compost down into biomass.

Read more about degradation initiators here.

Compostable Biodegradable Plastics

Truly biodegradable plastics are compostable.

Biodegradable products break down through a naturally occurring microorganism into simple, stable compounds which can be absorbed into the ecosystem. To be classed compostable, items must biodegrade within a certain time (around the rate at which paper biodegrades) For a man-made product to be sold as compostable, it has to meet certain standards. One such is the European Norm EN13432.

Compostable Plastics  meet all of these criteria. You can find out more here.

Infographic

Yes they have a vested interest making as they do compostable plastic goods but the info still stands.