Why Being Compostable Is Essential For Biodegradable Plastics
You may have seen the rise in interest, from both media and consumers, over biodegradable and compostable plastics.
These materials are advertised to offer a more sustainable way forward, when compared to conventional plastic, but what are the downsides?
In this article, we are going to look at several key aspects of biodegradable and compostable plastics, as well as dispelling some green myths nurtured over time.
Before we delve into the world of exactly what biodegradable plastics can do for us, we need to understand why they were created in the first place.
Conventional plastic, which most of us just know as 'plastic', is produced from fossil fuels, and does not have the ability to biodegrade.
This results in many of the problems we see arising today - the fossil base results in a high carbon footprint, the non biodegradability results in a build up of plastic in the natural environment, as well as the formation of microplastics as opposed to natural components.
There are seven types of conventional plastic in mass production, with a few common ones being PET (polyethylene terephthalate), PP (polypropylene) and PVC (polyvinyl chloride).
Now we know a little bit about conventional plastics, we can begin to discuss biodegradable plastics.
Bioplastics are similar to conventional plastics, in that many of them are both thermoplastics, and have roughly equivalent strengths and elasticities. However, bioplastics are produced from biomass, they can biodegrade, or both.
A few examples of bioplastics include PLA (polylactic acid), bio based polyethylene, and bio based polypropylene.
A key myth to get out of the way - just because a plastic is produced from biomass, does not mean it can biodegrade. This is shown with the bioplastic bio based polyethylene.
This also works the same for the other way round. Just because a plastic is made from fossil fuels, does not mean it can't biodegrade. This is shown in the bioplastic PCL.
On appearance, the fact that some of these bioplastics are biodegradable might seem a good thing. One imagines that if a material is biodegradable, it will degrade harmlessly into any environment it ends up in, within a short time frame.
These assumptions are incorrect.
If a material, say a PLA cup, is biodegradable, it just means that the cup will break down into biomass, CO2 and water with the aid of microorganisms.
There is no time limit attached to this biodegradation process, meaning that if a biodegradable cup biodegraded in 500 years, it could still legally be classed as biodegradable.
All the time during this period, the cup could still pose a threat to wildlife who mistakenly ingest it, believing it to be a source of nutrition.
There is also the concept that biodegradable materials will break down in landfill very quickly, which is also not true. If a PLA cup ends up in an aerobic landfill (with oxygen present) it will biodegrade, but at a very slow rate.
If a PLA cup ends up in an anaerobic landfill (with no oxygen present), it will in all likelihood just occupy space, and remain inert.
In the ocean, the necessary microorganisms might not be present in enough numbers to guarantee a quick biodegradation time.
PLA will continue to degrade however, through processes such as photodegradation, as will all plastics regardless of their biodegradability (this is how many secondary microplastics are formed).
This is why being biodegradable isn't good enough, and why we need bioplastics to be compostable as well as biodegradable.
If a material is compostable, it will biodegrade under set conditions, in a set time frame, to form compost. The key thing here is the set time limit.
We are going to be focusing on industrial composting in this article, as opposed to home composting.
Within industrial composting conditions, industrially compostable PLA cups will be fully composted within six months, with the average temperature required to be 58 degrees celsius.
The main issue with industrially compostable materials is that large scale composting infrastructure is not yet available. This means that if compostable materials such as PLA enter the public waste stream, they risk recycling contamination which can decrease the rate of recycling overall.
So how do we tackle this?
Our method is through LFHP Zero, which is our free compostable post back scheme for our compostable gifts.
With every order containing a compostable gift, we send a compostable mailing bag as well. When the compostable gifts have been used, simply send them back to us and we will pass them onto our industrial composting partners.
This is at no extra cost to the consumer, and we guarantee zero waste will go to landfill with all compostable items sent back to us using LFHP Zero.
Non Biodegradable Bio Based Bioplastics
To take a step away from biodegradable bioplastics, we can see how other groups are dealing with bioplastics as a whole in a more sustainable manner, than conventional plastics.
Bio based bioplastics are materials that are produced from renewable resources.
The previously mentioned bio based polyethylene, is a bioplastic produced from sugarcane in some cases.
It does not have the ability to biodegrade, which means recycling is currently it's best chance of not entering landfill, incineration or the natural environment.
Like PLA, bio based polyethylene has a reduced carbon footprint when compared to fossil based polyethylene, due to it's renewable base.
This is a result of the sugarcane used to manufacture the bio based polyethylene sequestering carbon from the atmosphere, and storing it. This means that the trapped carbon won't be released until end of life, where potential degradation or incineration will release the carbon.
Currently, the three main ways of dealing with our plastic waste are landfill, incineration and recycling. Landfill is not sustainable, both on an immediate level and a longer term level.
Leachate is the mixture of rainfall and toxic compounds in plastic waste, in the landfill.
As the landfill is rained upon, this leachate forms, and slowly makes its way deeper into the landfill, eventually reaching the ground water and surrounding soil. From these positions, the local environment is polluted, which could result in harm coming to local wildlife and plants.
On a longer term basis, landfill is not sustainable due to having a finite amount of space on this earth. Landfills around the world are filling up, and eventually there won't be any space left to put our waste.
Eventually, developed countries will begin to have this problem as well, if nothing is done to sort the inevitable situation that will arise.
This might be quicker due to developing countries sending their waste back to developed countries.
Developed countries such as the UK have chosen to export plastic waste for many years, with 611,000 tonnes of waste being exported in 2018. Now countries such as Malaysia are refusing to take in any plastic waste, and rightly so.
The UK will now have to put in place a practical solution to how we deal with our plastic waste.
It should not be considered to just simply find another developing country to send our waste too. As a country leading the way internationally in so many areas, we should be setting the example in developing sustainable waste management processes, that do not harm the environment.
LFHP Zero currently only applies to our compostable items, but we are working all the time on developing zero to landfill processes for all of our gifts, and all of the packaging.
In the future, our dream is to use returnable mailing boxes produced from renewable resources, which can be disposed of with zero waste going to landfill when they are not of a quality to be used anymore.
Using renewable resources will ensure that the boxes will remain carbon neutral, or carbon negative.
We want a delivery fleet, or work with a delivery service that use electric cars powered by clean energy. This will be another step in becoming a carbon neutral business.
We think the future of ownership will change dramatically from what we know it as currently. Many more products will be rented, and then returned, rather than being thrown away.
Ultimately, there is such a variety of different materials and different products, that the notion of relying on a public waste management system is a bit daft. We believe that a much more environmentally positive way of dealing with waste, is to have companies, like ourselves, developing specific processes for specific products.
We need to start viewing products as a circular, rather than just the traditional production, life and end of life view. We need to look at products through the lense of a journey, not just their use.
We need to start thinking of products as not what they are used for, but for the effects they have on our environment at every stage.
Companies should take ownership of any waste they produce, and develop schemes that work with the environment.
To Bio Or Not To Bio?
Bioplastics are undoubtedly our future, as we cannot continue to produce fossil fuel based plastics at the current rate, if at all. Climate change and plastic pollution are two threats that are only going to pose more risk as time goes on, and on a few different levels they are linked.
To make the transition to renewable based biodegradable plastic, we must have the correct infrastructure in place to prevent recycling contamination, and minimize waste sent to landfill or incineration.
The future can be bright, but we must act quickly and efficiently to implement the structures that will support it.