What are Oxo-Degradable Plastics and What’s Being Done About Them?

As consumer demand for sustainable products grows, bioplastics —which can reduce our reliance on fossil fuels and decrease greenhouse emissions— will become more prevalent. Production of bioplastics is expected to grow by as much as 20% by 2022, and as it does, consumer understanding of bioplastics will need to grow with it. A major source of confusion is the difference between three terms: Biodegradability, compostability and oxo-degradability. Although these terms are often used interchangeably, they are not synonymous. Confusion regarding common bioplastics terminology such as these, especially where it concerns the disposal of bioplastic products, can have dire consequences. Companies need to understand the distinctions between each category in order to accurately and honestly market their products.

Consumers need to understand these terms in order to make educated purchasing decisions and properly dispose of bioplastic products at the end of use. To understand these three terms (i.e., biodegradability, compostability and oxo-degradability), it is important first to clearly understand the definition of bioplastics. Bioplastics refer to a large family of plastics which are sourced from biomass at the beginning of their life (bio-based), metabolized into organic biomass at the end of their life (biodegradable), or both.

Nearly every material will biodegrade, given enough time. But the length of the biodegradation process is highly dependent on environmental parameters such as humidity and temperature, which is why claiming that a plastic is “biodegradable” without any further context (i.e., in what timeframe and under what environmental conditions) is misleading to consumers. Reputable companies will often make more specific claims, primarily certifying that their bioplastics are compostable. Compostable plastics are a subset of biodegradable plastics, defined by the standard conditions and timeframe under which they will biodegrade. All compostable plastics are biodegradable, but not all biodegradable plastics would be considered compostable.

While often confused with biodegradable plastics, oxo-degradables are a category unto themselves. They are neither a bioplastic nor a biodegradable plastic, but rather a conventional plastic mixed with an additive in order to imitate biodegredation. Oxo-degradable plastics quickly fragment into smaller and smaller pieces, called microplastics, but don’t break down at the molecular or polymer level like biodegradable and compostable plastics. The resulting microplastics are left in the environment indefinitely until they eventually fully break down.

Because oxo-degradable plastics are only degradable – not biodegradable or certified compostable –after the bio-additives have broken down traditional plastics remain. Even if the small pieces are microscopic, the plastic still exists and can easily enter the environment.  There are absolutely no benefits from using oxo-degradable plastics. Nearly every material will biodegrade, given enough time. But the length of the biodegradation process is highly dependent on environmental parameters such as humidity and temperature, which is why claiming that a plastic is “biodegradable” without any further context (i.e., in what timeframe and under what environmental conditions) is misleading to consumers.

Reputable companies will often make more specific claims, primarily certifying that their bioplastics are compostable. Compostable plastics are a subset of biodegradable plastics, defined by the standard conditions and timeframe under which they will biodegrade. All compostable plastics are biodegradable, but not all biodegradable plastics would be considered compostable.

According to the World Wide Fund for Nature (WWF), non-biodegradable plastic used for plastic bags will take 20 years to decompose, plastic straws 200 years, plastic rings 400 years, and water bottles 450 years. Symphony Environmental says that oxo-biodegradable material converts plastic products into biodegradable material through oxidation.

On its website, Symphony Environmental said: “Oxo-biodegradable plastic degrades and biodegrades in the open environment in the same way as nature’s wastes, only quicker. What’s more, it does so without leaving any toxic residues or fragments of plastic behind.” However, according to Reaven Services founder and packaging expert Abhishek Moon, oxo-biodegradable plastics use metal salts to start the degradation process, resulting in small plastic fragments.

Moon said: “Further degradation [of oxo-biodegradable plastic] depends on living organisms and bacteria. Products using this plastic typically don’t break down fully in normal landfills. This may be due [to] a lack of oxygen. Also, as another negative, some oxo-biodegradable plastics use cobalt and carry the risk of further environmental pollution.”

Moon also said: “[Oxo-biodegradable plastics] are made by incorporation of specific additives into traditional plastics such as Polyethylene (PE), Polypropylene (PP), Polystyrene (PS), Polyethylene Terephthalate (PET) and sometimes also Polyvinylchloride (PVC) at the moment of conversion into final products. The additives are based on chemical catalysts, containing transition metals such as cobalt, manganese, iron, etc., which cause fragmentation as a result of chemical oxidation of the plastics’ polymer chains triggered by UV irradiation or heat exposure.”

Taking Action Against Oxo-degradable Plastics

The European Commission has recommended EU-wide measures be taken against so-called ‘oxo-degradable‘ plastics. In a report, the Commission said that “a process to restrict the use of oxo-plastics in the EU will be started”. European Bioplastics (EUBP), the association of the bioplastics industry in Europe, strongly welcomes this clear commitment to take action. “EUBP has long been warning about the harmful effects of oxo-degradable plastics on the environment as well as the potential damage to the reputation and understanding of truly biodegradable plastics. Several cases of greenwashing and false claims have been reported over the past years that have lead to confusion about biodegradation in the general public,” says Hasso von Pogrell, Managing Director of EUBP.

 

The Commission makes a necessary and clear distinction between biodegradable plastics and oxo-degradable plastics, the latter of which cannot be considered bioplastics. They are conventional plastic materials with artificial additives that do not biodegrade but merely fragment into small pieces that remain in and potentially harm the environment and endanger recycling and composting.

The report states that oxo-degradable plastics fragment over time into smaller plastic particles, and finally microplastics. Furthermore, it states that there is no evidence that these “plastic fragments will undergo full biodegradation within a reasonable timeframe”. Other major concerns are raised with regard to the recyclability of oxo-degradable plastics as they cannot be identified and sorted separately with current technologies and therefore can negatively affect the quality of recyclate and recycled plastic products.

The term “restriction” can encompass a ban on the supply (provision or sale) and/or a ban on manufacturing. These restrictions are often accompanied by specified exemptions, for example, to cater for medical needs. Since leaving the EU, the Governments in both Wales and Scotland have chosen to link their restrictions to follow those introduced by the EU. The UK Government’s proposed restrictions for England are similar to the EU’s, but not linked explicitly.

The EU’s restrictions on single use plastic items have been added to the (amended) Northern Ireland Protocol to the UK/EU Withdrawal Agreement. This means that these EU restrictions apply in the UK in respect of Northern Ireland. Northern Ireland was given an extended transition date to implement these provisions by 1 January 2022, which has not been met. The Northern Ireland Minister of Agriculture, Environment and Rural Affairs has argued that implementing these restrictions is an obligation for the UK Government to deliver.

The Internal Market Act 2020, passed by the UK Parliament, established a principle of mutual recognition for goods. This means goods that have been produced or imported into one part of the UK, and which can be sold or supplied there without contravening any restrictions, can be sold in any other part of the UK, free from any restrictions which would otherwise apply. Any regulations banning the supply of single use plastic items would be subject to this principle.

The Scottish Green Party has expressed concern that the practical impact of the Act will undermine effort to restrict items in one part of the UK that have not been restricted in another. Cardiff university senior law lecturer, Dr Richard Caddell, said it, “places a ceiling on the ecological ambitions” of the devolved Governments. The 2020 UK Government policy paper, Goods market access: approach to restrictions and bans set out how any single use plastic ban would operate across the UK: “Devolved administrations could introduce a ban on the sale of a particular good, but the ban would only cover local products produced in that part of the UK (or those imported into that territory from outside the UK). Devolved administrations could not enforce that ban against sellers of goods produced in, or imported into, other parts of the UK.”

The UK Government has recently sought views on how to reduce the use of wet wipes, tobacco filters, sachets, and other single-use cups. The Welsh Government intends to consider interventions on wet wipes and equivalent products. The Scottish Government has previously sought views on placing market restrictions on wet wipes and plastic tampon applicators. It’s not yet clear whether or when any further restrictions on these items will be put in place.

Certain academics and consultants have cautioned that in some cases, banning plastic items can lead to unintended consequences, such as the items being replaced by more polluting alternatives. Some campaigns are now focusing on reducing disposable items more widely, not just those made from plastic.

As the UK is now in the process of revising legislation on the use of plastic packaging, now is the time to act. Overwhelming scientific evidence, including research commissioned by DEFRA and the EU, has demonstrated beyond doubt that the claims these additives transform polyolefin plastics into biodegradable plastics are unfounded. It is scientifically well-known that all polyolefin plastics are naturally prone to oxidation under environmental conditions. Such oxidation ultimately leads to fragmentation and formation of microplastics, which build up in oceans and in soil

As bioplastics continue to gain market share in the coming years, being clear about the environmental benefits in product and material marketing is imperative. Looking to the Federal Trade Commission’s (FTC) Green Guides is a good place to start. The Green Guides outline best practices for clearly labeling and marketing green products to ensure the expectations of the consumer align.

Not only will transparency allow consumers to make smarter purchasing decisions, but it will ensure bioplastics are disposed of through the proper channels. Ultimately, better end-of-life disposal of bioplastics strengthens their environmental value proposition of diverting organic waste from landfills, reducing greenhouse emissions and ensuring the sustainable consumption of resources.