The Science Behind Our Eco-Friendly Gifts: What Does 'Biodegradable' Really Mean?
In this blog, we're going to have a look at a key term that keeps popping up in advertisements for 'green' products. Being biodegradable sounds great, but what does it really mean? We are going to ask and answer questions on biodegradable products, their potential, as well as their pitfalls.
What Is the Definition Of 'Biodegradable'?
According to EU Bioplastics, the definition is as follows.
A material is biodegradable if it can:
"Break down into biomass, CO2 and water, with the aid of microorganisms."
Let's look at a couple of examples, that fit this statement.
An apple core ends up on a patch of land, let's say a field of long grass. As a result of the soil and environment sustaining high levels of life, the necessary microorganisms are present to aid the biodegradation of the apple core. The apple core will break down into biomass, CO2 and water. Typical times for an apple core breaking down are around one month.
This shows that biodegradation is not just down to the material breaking down, but to the environment in which the degrading is occuring in.
This is where things start to get a bit tricky. With the rise of plastic pollution, and the destruction it is causing on a global scale, come the alternatives that promise biodegradability. Straight off, you would hear the word 'biodegradable', and assume something like:
"If it's biodegradable, I can throw it on the ground and it will be gone in a short amount of time. It doesn't matter if it ends up in landfill, because it will biodegrade. It's ok for it to end up in the ocean, because it will biodegrade without harming any wildlife."
These assumptions are valid thoughts, but they are not true.
Let's take a biodegradable coffee up, for example.
If it ends up in the same field of long grass that the apple core previously mentioned broke down in, it is extremely unlikely to degrade within the same time frame.
We say unlikely, because it can't be conclusively proven one way or the other, as all the factors in this scenario are hypothetical. We would like to say 'it definitely won't break down within the same time frame' but we can't prove it.
Just because the coffee cup is biodegradable, does not mean it will break down within a reasonable timeframe. This means it could potentially remain in the field for hundreds of years, similar to its plastic counterpart.
If the coffee cup ends up in landfill, it also might not biodegrade. This is because landfills are often filled with a high density of waste, which means little or no oxygen is present. Some microorganisms need oxygen to survive. If they don't have any oxygen, they won't be able to aid with the biodegradation of the coffee cup.
If the coffee cup ends up in the ocean, it also might not biodegrade for the same reasons.
What Are Microplastics?
Going back to conventional non biodegradable plastic, let's talk about microplastics. As non biodegradable plastics don't have the ability to degrade into biomass, CO2 and water, they just break down into smaller and smaller pieces of plastic.
A piece of plastic less than 5 mm in size is known as a 'microplastic'. Microplastics can either be primary or secondary. Primary microplastics are produced to be less than 5 mm in length, such as microbeads found in cosmetic products. Secondary microplastics are formed from a larger piece of plastic degrading into pieces of plastic less than 5mm in size. These secondary microplastics can be formed from almost anything. Think plastic bottles, plastic cups, the list goes on.
Microplastics are dangerous, and pose a threat to the whole marine food chain. Through a process called the 'trophic transfer of microplastics', plastic accumulates at every step of the food chain. Eventually large predators such as seals, cod and humans (yes, that's right, us) ingest microplastics through eating prey with microplastic inside of them.
The current effects of microplastics for health are not fully understood yet. However, plastics are composed of some nasty chemicals, which have been linked to detrimental health defects. BPA, a chemical included in plastics such as PVC, is an endocrine disruptor. Being exposed to BPA could interfere with natural hormone activity. Researchers suggest that potential health problems from BPA exposure could result in an increased risk of birth defects.
Can Any Type Of Plastic Biodegrade?
There is also a slight confusion between what the material is made out of, and it's ability to biodegrade.
Just because a material is formed from fossil fuels, such as PET (a common plastic used to make disposable water bottles), does not mean it can't biodegrade. In other words, specific types of crude oil based plastic have the ability to biodegrade.
To go through this, let's talk about the difference between conventional plastics and bioplastics. Conventional plastics are produced from crude oil, and don't have the ability to biodegrade.
Bioplastics are similar to conventional plastics in their characteristics, but they are either made from biobased sources, can biodegrade, or both.
They are formed from crude oil, and cannot biodegrade. These factors make conventional plastic very harmful to the environment, in both production and end of life.
The process of producing plastics such as PET means the release of harmful emissions.
The climate crisis is actively worsened by fossil fuel based plastic, due to processes like fracking (hydraulic fracturing) being extremely carbon intensive.
The second group is the bottom right of the graph. Fossil based biodegradable bioplastics show that in order for a material to be biodegradable, it doesn't have to be made of biomass.
Plastics such as PBAT have been proven to biodegrade in agricultural soil. This group is comparatively stronger than conventional plastics due to it's biodegradabile potential, but it still is carbon intensive to produce.
The group in the top left of the graph, biobased non biodegradable bioplastics, are again more beneficial than conventional plastics.
Because bioplastics such as biobased PET, are produced from renewable resources formed from biomass, the sustainability of production is infinitely better. This is because one day, fossil fuels will run out.
Some predict this day will be in our lifetime. Because the raw materials are plant based, bioplastics like biobased PE are also far closer to being carbon neutral.
This is due to the plants used in production actively taking in carbon, and not releasing it until disposal. Over the course of it's LCA (life cycle assessment), biobased bioplastics will only release the carbon taken in during the growth of the plants that formed it.
The reason biobased bioplastics aren't completely neutral is due to the processes of production still potentially requiring fossil fuel input, such as the transport of bioplastics to distributors. As technology moves towards cleaner energy however, bioplastics do have the potential to become completely carbon neutral.
Finally, in the top right of the graph, we get to our favourite segment of bioplastics.
Biobased biodegradable bioplastics have all the features to be fully sustainable. They are produced from renewable resources, and have the potential to biodegrade fully.
Looking back to what was said previously with regards to what biodegradability actually means, just being biodegradable isn't enough.
To be truly beneficial to the environment, we need materials to not just be biodegradable, but compostable as well.
Why Is Being Compostable Important?
If a material is compostable, it can:
"Biodegrade within a set time frame, under set conditions, to form compost".
Being compostable allows the potential for a truly organic, closed loop recycling system. Bioplastics such as PLA fulfil all the criteria for being a game changer in fighting plastic pollution.
As you might have guessed, again, it is not so simple. There are two types of composting: Industrial and Home.
Understanding what the two types consist of is crucial, as many marketers are not specifying if their product is industrially compostable or home compostable. Let's break down what the differences between the two types of composting are.
If a material is home compostable, it will decompose in your typical home compost setting. Temperatures are not high, and average around 20-30 degrees celsius.
There are so many variables than can influence the temperature, such as location, time of year, local weather conditions, that the exact temperature range can't really be specified.
The main content of a home compost bin will be grass, food waste and garden plants. If a material is home compostable, it should break down within a year in a home compost setting.
Many biodegradable and compostable cups are not home compostable. They will be very unlikely to break down in a home compost bin, within a reasonable time frame. Compostable cups that are made of PLA, including our own, are what's known as 'Industrially Compostable'.
If a material is industrially compostable, it needs set conditions that are usually only found in industrial composting facilities. Temperatures are approximately 58 degrees celsius, and other factors including moisture and nitrogen ratio are fixed.
The most recognised set of standards for industrial compostability, is the EN13432 set of requirements.
If an item is industrially compostable to EN13432 standards, it will break down fully in 6 months in an industrial composting plant.
We've put together an infographic to show the main differences between home composting, and industrial composting.
In order to access an industrial composting site, we have developed LFHP Zero. We have partnered with an industrial composting facility, who have the ability to process any compostable waste we send to them. All used compostable waste will be fully composted, with zero waste going to landfill.
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Throughout this blog, hopefully we've fully answered your question on what 'biodegradable' really means.
A key thing to take away from here is to question any claims made by companies, saying they stock 'biodegradable' products. (That includes us!). Legally, they may have the right to say their product is biodegradable, but in reality the chances of their product actually biodegrading could be very small, or not at all.
Biodegradation depends just as much on the environment the material is in, as the material itself.
Environmentally Friendly Gifts
Reducing plastic waste being sent to landfill is at the forefront of our range of environmentally friendly gifts.
As well as ensuring that every one of the environmentally friendly gifts has no single use plastic, the same rule applies to the packaging they come in.
If you would like to read more about environmental key terms, feel free to subscribe to our email list at the bottom of the page.