So most plastics are made from oil and most plastics do not biodegrade. See how and why here…
But what does that actually mean?
Biodegrading
Biodegradation refers to the breaking down of organic substances by natural means. Natural means, means the breaking down is done by naturally occurring entities – things that are made in the body such as enzymes ( clever things that enable chemical break downs) or micro organisms that inhabit the teeny tiny world ( bacteria, fungi and exceptionally small plants and animals ). Any plant-based, animal-based, or natural mineral-based product has the capability to biodegrade
The key point is, is that the process of biodegradation is an integral part of the natural cycle. This process could be called rotting or decomposing or other nasty sounding things and yes it can be smelly but it is the very basis of life. Because as natural materials break down they release all kinds of nutrients that are used to feed other living organisms. Orange rind becomes compost which releases nutrients the orange tree can utilize. The tree feeds and so has the energy to make fruit which we eat discarding the peel which then biodegrades into compost – feeding many other creatures along the way including worms. It’s a kind of magic
In short…..
Biodegrading is the breaking down of organic substances, (plants, dead animals, rocks, minerals etc.), by natural means. It happens all the time in nature. We live, we die, we rot and so we feed the next generation. Even if you are a rock. All plant-based, animal-based, or natural mineral-based substances will over time biodegrade.
Here’s how long it takes for some commonly used products to biodegrade, when they are scattered about as litter:
Paper ~ 2-5 months 
Cotton rags ~ 1-5 month
Natural fiber rope ~ 3-14 months
Orange peel ~6 months
Wool socks ~1 to 5 years
Leather shoes ~25 to 40 years
Tin cans ~ 50 to 100 years
Plastic – years? centuries? maybe never!
Why Plastic Doesn’t Biodegrade
Because they are man made, the majority of plastics do not biodegrade. “Nature doesn’t make things like that, so organisms have never seen that before ” says Kenneth Peters, an organic geochemist at Stanford University, quoted in this fantastic article I recommend you read
Which means the enzymes and the micro organisms responsible for breaking down organic substances do not recognize plastic. Therefore plastic products are pretty much indestructible – they do not rot or biodegrade.
Except…
Plastic Eating Microbes
Of course it is not quite as simple as that. Some bacteria it seems can digest plastic. Don’t get too excited. They are rare and don’t eat a great deal but you can read the latest reports here
Biodegradable Musings
That said the term biodegradable can be difficult to define. It is often about the time something takes to biodegrade – the rate at which something breaks down. Arguably everything, even man-made products, will eventually biodegrade. However if it takes centuries to do so, it is generally considered to be non-biodegradable.
It also depends where a product is dumped.
Why Landfill Doesn’t Work
“Many products that are inherently biodegradable in soil, such as tree trimmings, food wastes, and paper, will not biodegrade when we place them in landfills because the artificial landfill environment lacks the light, water and bacterial activity required for the decay process to begin.”
This is why newspapers landfilled back in 1952 can still be easily read! The Garbage Project is an anthropological study ofwaste conducted by a group at the University of Arizona. From Greengood
Too Much Trash
The sustainable rate of biodegradation is only what an ecosystem can deal with. Too much and the microorganisms get overwhelmed and collapse sobbing, unable to cope.
Degrading
Of course plastic breaks, tears and degrades – but only into smaller pieces of plastic. Read more about that here
Useful stuff to know
Degradable, biodegradable or compostable
Read More
Compostable Plastics Index
Read More
Biodegrading and degradation – Plastic Lifespan,
Read More
Plastic eating microbes
Read More
Degradation Initiators & Degradable Plastic
Read More