The chemical nature of different bioplastics enables us to distinguish between them and classify them into two families of biobased and/or biodegradable plastics. This distinction must also be taken into account when considering the end-of-life of these bioplastic materials.
In fact, those which are structurally similar to existing polymers (e.g. biobased PET or PE) will have the same recycling possibilities at the end of their life cycle as their petrosourced equivalents. In the case of household plastic packaging recycling, the distinction is not technically possible with the means currently used for sorting after collection. These biosourced versions can then be recycled in the same way as conventional materials, without disturbing the quality of the recycled plastic.
On the other hand, bioplastics with new chemical structures will have to be considered on a case-by-case basis as new materials, some of which also have the capacity to be biodegradable. This means, for example, that new end-of-life recovery routes can be envisaged, including through composting or anaerobic digestion.
By reducing the volume of plastic waste left in the environment, this property can also be seen as a functionality that can be exploited to the full, depending on the application and use of the material.
Bioplastics recycling
Recycling polymers after use is now seen by public authorities as one of the solutions to be favored, particularly in France and Europe since the passing of the AGEC law in early 2020 and the European PPWR Regulation in 2024.
The emphasis is therefore on developing recyclable solutions that also allow the use of recycled polymers.
Bioplastics must therefore fit into this new model and demonstrate their ability to meet the various requirements.
The big question: can this bioplastic be recycled?
But there’s no easy answer to this legitimate question.
To determine a polymer’s suitability for recycling, the following points should always be considered:
- What kind of recycling are we talking about? Mechanical recycling has been the most widely used form of recycling for many years, but it is beginning to face competition from chemical and enzymatic recycling (see our definitions of recycling terms in our glossary).
- Nature of the material? In theory, all thermoplastics (polymers with the ability to be melted and remelted under the effect of heat ad infinitum) are mechanically recyclable, provided their properties are well preserved. However, this does not mean that they are.
- Which application? The fundamental point is to know how the end-of-life of my product is managed today. If it falls within the scope of an Extended Producer Responsibility (EPR) scheme, producers have the choice of setting up collective non-profit structures, known as eco-organizations, or forming their own individual system. In France, the oldest and most emblematic EPR system has concerned household packaging since 1992. In this case, best practice guidelines are drawn up, and product/material pairs with the best recycling potential are identified, then potentially collected, sorted and recycled. More and more channels are emerging, with different requirements and targets. It may also be the case that there is currently no channel for your product. In this case, apart from individual initiatives by manufacturers or groups of manufacturers, there is little chance of optimizing the end-of-life of your product.
Biodegradability and composting of bioplastics
The biodegradability of a polymer is a property that depends on its chemical structure.ADEME defines it in its data sheet as follows: “A material is said to be biodegradable if it can be decomposed under the action of micro-organisms (bacteria, fungi, algae…). The result is the formation of water, CO2 and/or methane, and possibly by-products (residues, new biomass) that are non-toxic for the environment”. It is this ability to be broken down that differentiates biodegradable polymers from those that are not.
It‘s important to distinguish between the origin of a material (whether or not it’s biobased) and its end-of-life properties (whether or not it’s biodegradable), which are in no way linked. There are biodegradable but non-biobased polymers (such as PBAT or PCL), and conversely, polymers derived from biomass but absolutely not biodegradable (such as biobased PE and PET).
Composting, on the other hand, is a process for transforming fermentable materials into compost, which can be used to improve soil fertility. It involves aerobic biodegradation (in the presence of oxygen) under very specific conditions.
In the field of compostable plastics, two main types of composting are often mentioned:
- Domestic composting (also known as Home Compost), which can be carried out by private individuals under uncontrolled or uncontrolled conditions.
- Industrial composting is carried out on dedicated platforms under regulated conditions.
These two possibilities differ mainly in terms of the temperature at which biodegradation of the product takes place, and the presence or absence of microorganisms that enable assimilation. These factors induce different decomposition kinetics depending on the nature of the polymers.
Methanization, which produces biogas, is based on biodegradation under anaerobic (oxygen-free) conditions.
Standards and certifications for biodegradable and compostable plastics
EN 13432:2000
It defines four criteria to be met(composition, biodegradation, disintegration and compost quality) for materials or packaging to be recovered in industrial composting.
NF T 51-800:2015
This more recent standard deals with the suitability of materials for home composting. In particular, it forms the basis of laws governing the use of single-use plastic bags for packaging goods at the point of sale, as well as routing films and other disposable cups and plates.
Variants of these standards are also used today to assess bioplastics biodegradation in different conditions and media, such as soil or seawater.
On the basis of tests carried out in accordance with the above-mentioned standards, it is possible to obtain commercial labels enabling appropriate communication.