Sustainability plays a large and important role in all areas of the economy - including the packaging industry. One way of making packaging products more ecological, if necessary, is compostable packaging. But is it really a useful alternative to packaging made from conventional or recyclable materials? We take a closer look at the advantages and disadvantages.
All bioplastics - right?
To understand what is meant by compostable packaging, one should also take a look at other common ecological declarations with which packaging is labeled. All too often, all categories are lumped together under the term "bioplastic," which regularly leads to misunderstandings.
Bio-based plastics are made from renewable raw materials. Corn, starch or cellulose, for example, are used. The proportion of natural materials can be 100 percent, but significantly lower compositions are also possible. A bio-based plastic does not necessarily have to be biodegradable. Bio-PET, for example, is made from Brazilian sugar cane but it cannot be biodegraded.
Biodegradable refers to the disposal of the materials. A plastic may be called biodegradable if it decomposes into water and carbon dioxide within an unspecified time due to biological processes. However, this does not include statements about the production of the plastic: This does not have to be based on biological materials.
Now that the terms bio-based and biodegradable have been clarified, the definition of compostable packaging becomes understandable: this refers to materials that decompose within a specified period of time through clearly defined processes and under specific conditions. Accordingly, it is a special form of biodegradable plastic. Mostly compostable packaging is made of polylactic acid (PLA).
When most people hear the word "compost" they think of a somewhat dingy, somewhat smelly pile in the farthest corner of the garden, with flies circling around it. But in fact, that represents only a relatively small percentage of composting systems, the so-called home composts. Industrial composting facilities account for the larger share.
During composting, biodegradable materials are increasingly decomposed by microorganisms. The humus material that is crucial in this process is excellent as a fertilizer, as it contains many nutrients, and so contributes to the growth of other plants. In a compost - whether in the garden or industrial - one tries to create the most perfect conditions possible for the microorganisms to do their work.
Open and closed systems can be used for home composting. In closed systems, very good conditions can be created for the microorganisms, which is why the organic waste also decomposes faster here. To achieve this, regular turning of the contents must ensure that harmful microorganisms - such as mold - have no chance. This is not necessary with open systems, as sufficient ventilation is always provided. On the other hand, the decomposition of the waste is much slower and depends on the weather conditions. All organic waste such as fruit and vegetable leftovers, garden waste or tea bags and coffee filters may be placed on a home compost. Compostable packaging is explicitly not included! However, this point will be discussed in more detail.
Industrial composting involves creating the ideal conditions for compostable material to decompose as quickly as possible. This includes controlling the oxygen content and the temperature, which averages 50 degrees or higher. So, unlike home composting, much higher temperatures are achieved, which also affects composting.
In order for packaging to receive the "compostable packaging" label, it must meet several characteristics:
Compostable packaging is relatively rarely offered in retail stores, but consumers can choose from a wide range of products online. Some suppliers specialize in sustainable packaging, while others see the products as an additional offer for their customers. Some examples of compostable packaging are shipping bags, packaging chips as filling material for boxes, special bubble wrap, food packaging such as cups, bowls, plates or platters, packaging film, labels and CD, DVD or book packaging.
To answer this question, you first have to consider what packaging is actually used for. They should
Compostable packaging makes sense if it has all these properties without any limitations compared to conventional plastic. Otherwise, the products are sustainable, but still not alternatives - after all, a drinking cup that starts to decompose when it comes into contact with liquids would be extremely nonsensical.
Especially for packaging used in direct food contact, the safety of the contents and the consumer is a priority. Otherwise, the packaging has no purpose. If you still don't want to do without sustainable food packaging, we recommend our stand-up pouches made of 100% recyclable mono-plastic, for example.
Compostable packaging sounds good, but it is only a limited sustainable alternative. According to the current state of affairs, much more efficient and ecological is effective recycling or the use of products that are designed for multiple use. This is also the conclusion of the German Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection, which describes the packaging as not a good alternative.
So at first glance, the principle of compostable packaging looks good; nevertheless, so far it only accounts for a small part of the total volume. So in which areas do we already find compostable packaging? And when do they make sense at all?
Many in the industry are weighing up the pros and cons of plastic compostable packaging — could it really be the silver bullet they been looking for?
Compostable packaging, when properly processed, can be used in soil (Credit: Pixabay)
With most traditional plastics taking more than a century to degrade, innovators and packaging developers are increasingly looking towards the potential benefits of compostable solutions.
The idea of plastic and polymers that can be broken down quickly is not a new one, with products first introduced in the 1980s after Japanese scientists discovered a strain of bacteria capable of breaking down nylon.
Although biodegradables can be broken down far quicker than conventional materials, there are pertinent differences between these and compostable packaging.
Biodegradable plastics can be biologically broken down, but if this is carried out in soil, it can leave harmful toxins in the surrounding area.
Compostables are predominantly plant-based materials, which can be naturally degraded into soil without leaving toxic residues.
This type of packaging’s biggest benefit is, when disposed of and processed in the correct way, it can be turned into natural materials, such as soil or compost, at a much faster rate than traditional plastic counterparts.
When being processed through anaerobic digestion facilities — the breaking down of organic material by micro-organisms in the absence of oxygen — it can be turned into renewable energy.
HuaWei Product Page
One of the biggest problems surrounding compostable plastic is the problem of cross-contamination.
Products are recycled in material recovery facilities, which use optical technology to view and sort waste.
If compostables enter the recycling stream, they can contaminate the batch and make it impossible to process.
Speaking at this year’s Packaging Innovations conference, recycling firm First Mile CEO and founder Bruce Bratley said he believes this problem, alongside mixed-material packaging, is a big factor behind the UK’s low recycling rates.
He said: “Everything is recyclable in theory, but in practice, it’s not.
“And in practice, the recycling industry in the UK has got really low recycling rates, and those recycling rates are going down.
“This is because people are innovating. And they’re innovating with composite materials.
“Our plea is for people to choose one polymer, ideally, or a few polymers, and stop innovating across material streams and start innovating down one route so the recycling industry can get organised.”
One way figures in the compostable packaging industry are trying to tackle this issue is by creating a method for facilities to know and understand what materials look like.
Bio-based and Biodegradable Industries Association chairman Andy Newman said: “A water-marking system is being heavily worked on, so when they get taken into a recycling facility, the system can recognise which are compostable and which are not.”
Due to the types of conditions needed to compost this type of product effectively, it has to go through specially designed anaerobic digestion facilities.
As of summer 2019, there are more than 648 plants in operation in the UK, mainly dealing with food waste.
“We’re talking about materials which are essentially from renewable resources, in the main, there are small amounts of fossil-based materials which come in to improve functionality, but increasingly they’re more and more renewable material,” explained Newman.
“The vision for our materials is to operate in places where you can effectively take that material, put it in with your food waste, your food waste is collected from home, and then that goes off towards composting systems.
“In the UK, we have a mixture of industrial composting, conventional composting, we also have anaerobic digestion, which creates renewable energy, the vision in the future is to link the two together.”
One issue currently being experienced when it comes to compostable packaging being put through the anaerobic digestion waste management system is the fact it’s usually seen as a contaminant.
“A compostable system is sustainable, but currently we don’t have any system like that. If you currently put a biodegradable piece of plastic into your food waste, most anaerobic digesters who will receive your food waste will remove it,” explained University College London professor of materials and society Mark Miodownik.
“These conditions are not compatible with the bio-degradable plastic, so they get rid of it.
“The other reason they get rid of it, is that they can’t tell the difference between you putting a normal piece of plastic in and the biodegradable, even though perhaps you know the difference.
“When it comes to a mass system, they have no idea. So they just remove it, it gets burned.
“That’s bad. It’s bad for the environment. And it’s not a system that currently works at the moment.”
One of the biggest issues some see with compostable packaging is the much wider problem in the recycling industry in general, how consumers dispose of the packaging waste in the first place.
Bartley said: “In theory, if everybody put their compostable packaging into the food waste bin, that’s fine.
“The infrastructure is here today, but people chuck everything into everything, and there is no segregation whatsoever.
“And the problem, I think, with rolling out a solution is you are still going to end up with plastics in the food waste, and composters can’t take that.
“It then ends up in the organic material, which has been sold or given away to farmers — farmers do not want crisp packets and bits of plastic laying around their fields.
“So, we have to do be able to either move completely away from plastics and into compostables entirety, I’m really happy with that, or we have find a way of getting the plastic separated from the compostables.
“And the only way we’re going to do that is if the 60 million people in the UK do it.”
If you want to learn more, please visit our website compostable courier bags.