Danone was one of the first to use it on a large scale. It has been more than twenty years since the French food company brought the first compostable yoghurt pots into circulation. Then, around 13 years ago, came the launch of Activia yoghurt pots made from the bioplastic PLA. The material for PLA was obtained from maize, but according to the company management, this was only the beginning: In the medium term, the aim is to use "agricultural residues and recycle PLA packaging back into PLA".
In 2020, the Dutch biochemical company Avantium announced its intention to develop new biopolymers that will be used primarily in beverage bottles. The basis: sustainably grown sugar plants. Companies such as Carlsberg, Coca-Cola and Danone have been named as development partners.
Big plans, supported by big names. So why is there so little realised packaging on the market?
Plastics: almost exclusively conventional
It's a bit like David versus Goliath. Around 98 per cent of all polymers - commonly known as plastics - are based on crude oil and its products. Only two per cent of the total are bio-based.
So far, it has been difficult to imagine packaging without plastics and sales volumes have only been increasing for decades. However, much can already be substituted today, for example by fibre packaging made from renewable raw materials, by reducing packaging or by switching to reusable containers or refillable consumer containers. However, there is still very often a high penetration of plastic, especially in food packaging, although some fibre-based packaging and alternative barriers can offer the same protection. "A changeover usually means more than just a change of material; the entire supply chain has to be considered. If it's a change of raw material (from fossil PE to bio-PE), it's usually purely a question of money, because the bio-based solutions are usually more expensive. When switching from PE to PLA - assuming that PLA fulfils the same barrier requirements - all machines have to be readjusted, storage times have to be taken into account, climatic conditions on the transport route and in the destination country, and much more. Sometimes the switch simply fails due to the available quantity," says Pacoon Managing Director Peter Désilets.
Bio-based plastics are an obvious solution in some cases. They are created by polymerising renewable, non-fossil materials and are also biodegradable in many cases.
What is it all about: What are bioplastics? And what are biobased plastics?
Bioplastics is basically an outdated term - at least in German. This is because plastics are now also regulated in the Packaging Act as chemically modified substances. Substances that are not chemically modified are not categorised as plastics. This applies to many materials such as starch, barrier coatings, etc. This also has financial implications.
But let's stick with the term 'bioplastics'. Strictly speaking, it refers to "plastics" that are either of biological origin and/or biodegradable. However, the term is often confused with biodegradable materials. This in turn creates a certain lack of clarity, which is not particularly useful for the topic. Peter Désilets says: "Unfortunately, the issue has become even more complex due to legislation. This is because previously clearly defined 'bioplastics' such as PLA now also fall under plastics, which have been banned for some disposable products such as straws. They are therefore effectively equated with PE or PP, which are made from around 99% crude oil. When it comes to how these materials are used in packaging and how they are disposed of, a distinction is made between chemically modified materials - which includes PLA - and non-chemically modified materials. The latter should then no longer be called plastic. But there is no new term for this yet, so it's still a grey area at the moment."
However, the distinction between bio-based and biodegradable plastics is crucial to understanding the environmental impact and applicability of these materials. Bio-based plastics are made from renewable raw materials, such as vegetable oils, starch or cellulose. These materials can replace fossil-based plastics in production, which usually leads to a reduction inCO2 emissions.
Why bio-based does not equal sustainable
However, the bio-based origin does not automatically mean that these plastics are also biodegradable. Bio-based plastics such as bio-polyethylene or bio-polypropylene have the same properties as their fossil-based counterparts and are therefore not compostable or biodegradable.
On the other hand, there are also a few biodegradable plastics that can be produced from fossil-based raw materials. These materials are designed in such a way that they can be broken down under certain conditions. However, degradation is often only efficient in industrial composting facilities or certain environments, which means that they do not necessarily degrade faster in nature than conventional plastics. An example of a readily degradable fossil plastic is PVOH - which is also often used as a barrier in packaging. Rinsing and washing pods are sometimes also made of this material, which then dissolves during washing.
The possible raw materials are also diverse. Starch and cellulose from sugars are used, but also sugar beet, sugar cane and maize or certain types of wood, from which cellulose is obtained. The long list of raw materials also includes vegetable oils, gelatine and many others.
Incidentally, bioplastics are not a recent invention: celluloid, one of the first bioplastics, was created 150 years ago. Rubber and cellophane also belong to this category, as do PLA, bio-PET and bio-PE.
Fossil-free, recyclable, biodegradable: what speaks in favour of bioplastics
The potential advantages of bioplastics are obvious. First and foremost, the fact that no fossil raw materials are involved in their production speaks in their favour. If the packaging in question is collected via the established cycles, it can also be converted into energy through incineration.
The balance is even better when it comes to recyclable plastics, such as bio-polypropylene or bio-polyethylene. The chemical structure of these so-called drop-in bioplastics is identical to that of conventional PP or PE, so they also behave like their established siblings when it comes to recycling.
And finally, there is the group of bioplastics that are biodegradable. If this packaging is not disposed of properly, some materials at least decompose and leave no or at least less harmful residues in nature. But biodegradability depends on many factors, says Peter Désilets: "But be careful: not every biodegradable material breaks down under all conditions. Be it the dry desert, the salty sea, the freshwater river in the tropics, the mouldy, shady forest floor or the landfill. If the combination of air, light and temperature is not right, then it will be difficult to decompose. The same applies to compost in your own garden - only well-maintained compost provides good nutrient soil."
Infrastructure and processes: What speaks against bioplastics
So what's the problem? For Peter Désilets, Managing Director of Pacoon, an agency specialising in sustainable packaging, it is primarily an infrastructure issue. This is simply not available for sorting and recycling in many countries. "In most EU countries, bioplastics are not subsidised, so the quantities used are low and for the small capacities, it is not profitable to sort them from the yellow bag or carry out a longer process at the recycling centre. In the case of garden waste, these products usually cause problems because they degrade more slowly than normal garden waste consisting of leaves, grass and small branches," says Désilets.
Another obstacle is the lack of process chains. While these have long been established for petroleum-based products, there is a lack of capacity at every turn when it comes to bio-based plastics. Almost ten years ago, the bioplastics industry was already predicting rapid growth in production. The result has been slowly but steadily growing volumes. "Plastics or chemically unmodified materials for packaging can be produced from most known biological raw materials, the knowledge is available. The crux of the matter, however, lies in the refineries that produce the quantities. These have to be built up and sales volumes are needed to recoup the investment," explains Désilets.
When consumers have doubts - packaging under suspicion of greenwashing
There is also a certain image problem. In view of consumers' heightened sensitivity to greenwashing, organic plastics are walking a fine line.
Danone had to experience this. The company cooperated with WWF Germany in the development of its yoghurt pots and had the positive properties of the material confirmed by the Heidelberg Institute for Energy and Environmental Research. According to this institute, the production of the new pot produces 25 per cent fewer greenhouse gases and the consumption of fossil raw materials can be reduced by 43 per cent. The fact that the maize is produced according to social and ecological criteria is certified by the ISCC standard seal. And yet it was criticised.
"Unfortunately, the launch was somewhat 'exaggerated' in terms of communication because Danone said that the cup was better than the standard polystyrene PS cup. However, at the time, both cups were on a par - which in itself was a positive thing. However, the statement met with disapproval from Deutsche Umwelthilfe, which would like to see yoghurt in reusable containers. The environmental organisation therefore went to court and demanded that the statement be discontinued and the case went through the press - and many dairy companies were pleased that the competitor had been punished. The consumer didn't notice any of this. But the case meant that for years hardly any company dared to go public with more sustainable or even bio-based packaging solutions. An initiative that was laudable in itself was thus turned into a negative through communication," says Peter Désilets about the need for well thought-out sustainability communication.
Does bioplastic prevent recycling and composting? And what about agricultural land?
One important argument concerns the psychology of consumers. And this in turn has to do with the unclear terminology. For example, the word "bioplastic" suggests that the packaging would decompose quickly and without residue in nature or through composting - which would lead to a single-use culture because many consumers would not even think of recycling the packaging. In reality, however, this has not happened.
And even those who take proper disposal seriously don't have it any easier now. The already rampant uncertainty among consumers about what to put in the organic waste bin, yellow bag, residual waste or compost will not necessarily diminish, especially as some companies are communicating that some bioplastics can be disposed of in the organic waste bin. However, this is not legally permissible because the organic waste bin is not a recognised disposal method. Strictly speaking, this makes you liable to prosecution.
Peter Désilets counters the often-heard argument that arable land should not be used for industrial production with two strong arguments: on the one hand, the area used for bio-based plastics is not even one hundredth of that used for pure energy production. And on the other hand, the amount of land that is wasted on food that is ultimately thrown away in Germany alone is as large as the amount of agricultural land required worldwide for bioplastics. The Federal Environment Agency also cites competition for alternative land uses as an argument as to why it does not consider bio-based plastics to be more environmentally friendly than conventional plastics - unless residual materials, for example from agriculture, are used to produce bio-based plastics. Unfortunately, the Ministry of Energy is very quick to turn a blind eye when it comes to the use of agricultural land for bioenergy. In any case, it would make more sense to first use the plants for packaging, recycle them if necessary and then burn them at the end of their life cycle and thus utilise the energy - or as a nutrient for soils through composting.
Which brings a third argument into play: Increasingly, biogenic waste rather than plants is being used as a raw material.
PLA, food waste, new deposit systems for plastic: why plastics research is encouraging
The discussion about bioplastics may be somewhat dormant - but the corresponding research is not. And Sleeping Beauty's awakening was, as we all know, a triumphant one.
The Institute for Bioplastics and Biocomposites at Hanover University of Applied Sciences and Arts (IfBB) is pursuing several approaches at once. The "AddEgg" research project, for example, is about feeding the vast quantities of eggshells produced in industrial food production into the plastics industry. The calcium carbonate it contains has the potential to increase the durability, functionality and sustainability of bioplastics.
Research is also being conducted into ways of developing environmentally friendly and recyclable reusable trays with lids made from bio-based plastics that can be circulated in the German deposit system for "to go" food and at the same time remain in the material cycle at the end of their life cycle through recycling. Even asparagus trays are being considered here as an alternative raw material. At the same time, the IfBB is participating in a test for a new deposit system for reusable tableware. The researchers want to compare bio- and petroleum-based plastics and recyclates and develop a market-ready product that minimises the use of disposable tableware.
The IfBB researchers are also working on drinks crates made from bio-based polymers and plastic packaging for food made from polylactic acid blends. PLAs are considered to have a particularly promising future, as they are biodegradable and can replace PE and PP packaging in particular. PLA is also the focus of a research group at the Fraunhofer Institute for Applied Polymer Research IAP. They have developed a flexible and recyclable film material that can be used as packaging, but also in the automotive and textile industries, for example. The material is now being commercially produced by the Polymer Group as a new type of bioplastic.
A team at Virginia Tech wants to use microorganisms to convert food waste into fats, which in turn can be used to produce bioplastics. This would kill two birds with one stone: the waste would be put to good use, and at the same time the compostable materials would help to avoid microplastics and ultimately millions of tonnes of plastic, especially in the world's oceans.
But it is not only on land that there are resources for bio-based materials, packaging and barriers. In the water, too, people are busy 'collecting' and researching analogues for packaging components. Seaweed is a thorn in the side of many beach holidaymakers, but it is to be used as a fibre. Alginates can produce films or barriers with special functionalities, which are already in use. Shells that stick to wet rocks and can withstand rough seas are to be used as a resource for adhesives. New resources are also being extracted from other waste. The waste water from paper recycling is said to contain many important minerals and metals that are to be recovered. Materials that 'went down the drain' yesterday are to be recycled again in the future.
"Bio-based materials could be a solution for many issues that are currently the subject of much debate. However, politicians and the industry should focus on the key objectives: CO2 reduction and recyclability or environmental protection. Bio-based raw materials as a replacement for expensive recyclates, e.g. from chemical recycling, can be produced with dramatically lower CO2 emissions and have already been developed in terms of production technology. It would only be necessary to redirect capacities from bioenergy production and 'incineration' to packaging utilisation in order to ensure availability. This would also reduce the price. It would be quicker and cheaper than developing new processes for chemical recycling, which in turn would jeopardise mechanical recycling," says Désilets.