...compostable, degradable, biodegradable
This terminology is a minefield. As we care more and more about our planet, we all want to get it right. We want to dispose of materials in the correct way, where they can do the least possible harm - be that the recycling, the compost, or as a last resort, the landfill bin. But as the trend for a sustainable community grows, so to do throw away comments like, ‘It’s ok, it’s degradable’. What does that even mean? And does it make it ok?
I can tell you right now from the outset that this blog post might leave us all with more questions than answers. For example, at home I am currently using the bin bags pictured below. I diligently researched and read-up before I bought them. They claimed that the bags will degrade into carbon dioxide, water and a small amount biomass; that it will only take a year and they won’t leave any harmful residue. Having now read further into these terms of biodegradable and compostable, I am not convinced that their selling point is 100% possible.
I think, realistically, all I can aim to do in this post, is give you a heads up, much like my ‘bamboozled by eco’ article. That way you will hopefully not jump on a bandwagon, or start buying products because they report to be compostable without looking into the small print.
One thing is for sure, normal plastic is harmful when thrown ‘away’. Mainly because it will never go ‘away’ but instead exists forever on this planet somewhere. It will start to break down over time, and might exist in a form too tiny for the naked eye to see, but it will still be there.
Normal plastic is made from petroleum based solutions. Degradable plastic has an added chemical that allows the plastic to break down at a faster rate than normal plastic. However, that break down will never convert the plastic back into natural materials. It will remain as plastic, just in smaller pieces. So, in terms of harmful effects it is no better than normal plastic. In the end, it produces the same microplastics, just faster. In fact, in some ways, that makes it worse as it is therefore much harder to clean up. People doing a beach clean for example, wouldn’t be able to pick up these tiny microplastics as they would be invisible to the human eye.
So, what happens if we put the term ‘bio’ in front of this? Biodegradable plastic is made from a plant-based material, not petroleum. This means that the material will be broken down in a more natural way by things such as fungi or bacteria, until it is eventually all a natural material again. Hurray I thought, so there we have it … sadly, not that simple!
In order for this biodegradable process to work, there have to be specific conditions in place. The temperature needs to reach 50°C and the material needs to be exposed to UV light. My thinking is that if, for example, a biodegradable carrier bag enters the British water ways via a river or a canal, it is very, very unlikely it will ever reach 50°C and would therefore not degrade. If it is trapped in landfill under a ton of other rubbish, I am imagining it will not be exposed to UV light, and would therefore not degrade. Can you see the problem? If it is in the perfect conditions, it will become water, carbon dioxide and biomass. But, as with the bags I diligently bought to replace the black bin liners at home, I am not convinced a lot of our rubbish will ever find itself in these conditions.
Next up we have compostable. This means it will decompose into natural elements that are rich in nutrients and great for plants. I am sure a lot of us have a compost bin in the kitchen for all the scraps, so what happens to this waste?
As with ‘biodegradable’ there has to be certain conditions in place for compostable materials to become compost. If the conditions are met, it will produce the natural decay or rotting process that you would find in nature. The waste needs to be mixed with water, air and soil to enable the microorganisms to emit carbon dioxide creating the necessary temperature. If this process takes place it will produce perfect compost.
You might have a compost bin in the garden, you might have a bin for kitchen waste that the council take away each week. Are they doing the same thing? The majority of Council collections will take your waste to an industrial composting facility. Here it will be closely monitored! There will be tight regulations they adhere to, to ensure the temperature and atmosphere are perfect. As a result the waste composts down much quicker. A compost bin at home in the garden might not always be the right temperature, especially in the British climate. It also relies on you to turn it, mix it and add water. However, eventually your home compost will produce compost.
The other main difference between the two is what you can put into the bin. At home, meat and dairy products, bread, food scraps from your plate etc are not advisable as they won’t breakdown and may attract vermin into your garden. But, some Councils state that these items can be put in. If in doubt, your Council website will give clear instructions. As every council system is different, it is best to check before you use it.
At the moment plenty of products are trying to tell us loud and clear that they are biodegradable, compostable and not made with plastics. The cups pictured here have been introduced into the meeting rooms at work and Teapig state that their tea temples (ie pyramid shaped tea bags) are compostable. However, if you look at bit deeper at the small print, they are only compostable in an industrial setting. Which is great if you have a council collection, not so great if you are putting items in the garden. I consulted my gardening oracle on this one - my mum. She said she has always put tea bags in the compost on the allotment and they will compost down, it might just take a while.
However, just to add to the dilemmas we are facing, even our British cup of tea is not safe. Tea bags normally contain polypropylene plastic. If normal tea bags go into the composting system, the plastic will be in the compost at the end, which is not desirable. You might think a tea bag is small, it is an insignificant amount of plastic. Well then, think how much tea this country drinks altogether! A recent article by Country Living outlined what different brands are doing about this. PG tips have announced that they will remove plastic by the end of the year, as have Co-op in their own brand 99 tea bags. In the meantime, it states Twinnings, Clipper, Pukka Herbs, Aldi Specially selected range and Waitrose Duchy range are all plastic free, as are Teapigs mentioned above.
As I said at the beginning, I am not sure I am any more in the know now than before researching for this blog post. There is, however, one thing I feel certain of:
It is not ok to say ‘It’s ok it’s biodegradable’. Instead, find an alternative that can be reused over and over again. A cloth bag that will be used endlessly is still the best option over any biodegradable / compostable plastic bag.