UCL study flames oxo-biodegradable plastics controversy as industry denies greenwashing and sidesteps bans
19 Jun 2023 --- Oxo-biodegradable plastics, which use various forms of additives to break down polymers in the natural environment, are under increasing scrutiny following the release of an extensive study review conducted at the University College London (UCL), UK.
The findings could lead to an expansion of existing international bans on the materials and are fueling an ongoing 40-year legislative and scientific debate, which has already caused numerous litigation cases, accusations of defamation and claims of violent personal threats to industry critics.
Also known as pro-oxidant additive-containing (PAC) plastics, oxo-biodegradables are defined by the UCL review as any polyolefin plastic (typically PE, PP, HDPP, LDPP) that contain metal additives like magnesium, cobalt, manganese, copper, cerium or nickel, or in the form of salts like carboxylates, dithiodicarbamates, acetylacetonates, or organic complexes like carboxylic acid.
These additives can catalyze (in hot, dry climates) the breakdown of polyolefins in the natural environment and are said – by proprietors – to leave behind no microplastic pollution or toxicity. Proponents maintain these designs are a revolutionary solution to the world’s plastic pollution crisis, and some countries have been convinced to make them mandatory by law.
But UCL’s review found little to no evidence of the environmental claims made by companies still selling PACs in regions where bans have yet to be enforced. The findings show there is no evidence that biodegradation is catalyzed in temperate climates like the UK and that the degree of microplastic pollution and toxicity to microorganisms is unknown.
The UCL study review found no evidence that PAC plastics do not cause toxicity or microplastic pollution.Oxo-biodegradables are currently outlawed in the EU, and critics accuse Western companies of continuing to peddle PAC plastics to profiteer from largely uninformed, undeveloped and vulnerable nations where legislation has yet to be enforced – the Middle East and East Asia being prime examples.
Scientific “disconnect,” legal frameworks
At the heart of the controversy surrounding PACs are legal standards established by numerous scientific investigations, including those reviewed by UCL.
The review found that the British Standards Institute’s (BSI) current measuring method (PAS 9017 : 2020), which tracks biodegradation timescales, shows most PAC plastics have biodegradability values in the range 5–60% and would not pass relevant criteria for licensing.
The review also shows there is so far no evidence that microplastic pollution would not result from these additive-driven material breakdowns.
In the EU, a 2018 European Commission report called for a process to begin restricting oxo-biodegradables in the absence of any provable beneficial effects. Bans were enforced in France and Spain, and the EU Single Use Plastic Directive (SUPD) has now implemented a total outlaw throughout the bloc.
In the UK, a government consultation was launched in 2019 to gather evidence on the viability of biodegradable plastics, which resulted in a 2021 declaration that oxo-biodegradables could be prohibited.
In the US, the Federal Trade Commission sent 15 cease and desist letters to companies marketing plastics as oxo-biodegradable.
The European Bioplastics association says it 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.”
Industry bites back
Despite the weight of evidence gathered in UCL’s review, stakeholders in the oxo-biodegradable market accuse the review authors of vital omissions and misunderstandings.
PAC plastics are marketed as a solution for countries that lack waste management infrastructure.
UK-based Symphony Environmental, which has been fighting for legislative approval for years, and is currently suing the EU for costs that could run up to £82 million (US$103 million) from loss of profits, reputational damage and loss of company value, has challenged the study.
In an official response to UCL’s findings, Symphony highlighted findings from a Eurofins laboratory report that shows 88.9% biodegradation and another from Intertek, showing 92.74%.
“Oxo-biodegradability is the only way to remove enough plastic litter from the open environment, and if it had been widely adopted when it was invented, there would be no ocean garbage patches,” states the report.
“There is now an urgent need for wide adoption of this technology before the problem gets even worse.”
Michael Stephen, director of Symphony, tells us the company is impelled to take legal action against anyone spreading “misinformation” or conducting “bad behavior” when addressing oxo-biodegradables as a result of financial damage.
Polymateria’s patents
Another prominent name in the PAC debate is UK-based Polymateria, a spin-off company from the University of Imperial College London, UK, run by CEO Niall Dunne.
Founded in 2016, Polymateria raised £15 million (US$19.2 million) from Planet First Partners and recently landed £20 million (US$25.6 million) in a series B round led by ABC Impact and Indorama Ventures. UK King Charles III also publicly endorsed the company’s R&D efforts in a 2019 tour of Polymateria’s laboratories at Imperial’s White City Incubator.
However, following the evidence in the UCL review, Polymateria’s global head of public affairs and regulatory strategy, Steven Altmann-Richer, tells Packaging Insights the company’s technology does not fall within the remit of PAC plastics and that he supports banning oxo-biodegradables. 
Polymateria claims its products are not PAC plastics despite the remarkable similarities shown in its patents.
But the company’s patents appear to show a number of identical chemical makeups to PACs, including transitional metal additive compounds reviewed by UCL and of other companies still using the term “oxo-biodegradable.”
Instead, Polymateria terms its products “biotransformational.” The company claims it has discovered a unique method to predict a set period of degradation time after which the crystallinity in a plastic product can be attacked and transformed into a “wax-like” state, which can then be turned into a prebiotic form that will be attacked by microbes, fungi and bacteria, turning the plastics back into a natural state.
Taxonomy tricks?
Since the release of UCL’s review, Polymateria has invited the university's researchers to visit the company’s labs and see evidence it says is not included in the review.
When asked about the similarities between the company’s patented products and the PAC materials reviewed in the study, Altmann-Richer says distinguishing features cannot be disclosed for business purposes.
“In line with intellectual property best practice, our patent does not divulge our full technical capability. Furthermore, our know-how is even more pertinent and is not shared anywhere,” he says.
“Our customers have data showing full biodegradability without any microplastics,” he further claims. “The UCL study did not review this data and did not conduct any studies based on our technology.”
Environmental threats
If PAC plastic designs and the claims made of them are true, it would mean a near panacea for plastic pollution, particularly in developing nations largely devoid of waste management infrastructure.
Areas in the Global South, for example, could rest assured any packaging discarded in the rivers and streets would harmlessly disappear within a short time frame (typically one to two years).
Critics, however, assert these supposed shortcut techniques could encourage littering and boost pollution levels throughout unprotected global regions, as well as discourage more effective solutions like reduction, reuse and redesign. 
PAC plastics are currently banned in most of the Western world.
Moreover, PACs that end up in landfills, for example, would not be rendered effective by the oxidative processes that define them through the required aerobic environments.
“Studies and literary reviews have been going on now for more than 40 years, but it seems unlikely that all scientists will ever agree with each other on this subject (or on most other subjects),” adds Stephens at Symphony.
Will litigation force legislation?
Whatever the legislative and industrial impact of UCL’s study, a central theme behind Packaging Insights’ investigation has been the refusal of any PAC plastics critic or scientist to go on record about specific companies or stakeholders.
While the environmental and human health threats potentially posed by PACs are detailed in the study review, some industry experts claim their criticisms – posed before the review was conducted – have been met with highly aggressive action from unnamed PAC companies throughout the past several years.
David Robert Newman, managing director at the Bio-based and Biodegradable Industries Association and chairman of the European Bioeconomy Bureau, says he “has been threatened, as have my friends, spat upon, received disgusting phone calls to my office, threats of violence and sued for defamation.”
No specific PAC producers and proponents are named in Newman’s claims, but mainstream media such as Bloomberg Europe, Bloomberg Green, Financial Times and Forbes have all reported on the purported benefits of PACs.
Polymaretia, for example, was recently interviewed by Bloomberg, in which the company’s CEO Niall Dunne said he is confident major deals will be made with some of the world’s biggest FMCGs and plastics producers in the near future.
“I’m very confident we’ll be back to you later this year [with news] that we’ve partnered with one of the largest brands in the world,” he said.
The company’s central target markets are largely in Asia, he says – counties flooded with plastic pollution in the open environment. “Nothing is off the table at this point,” he asserted.
Packaging Insights will continue to investigate the PAC plastics market from all sides of the debate.
By Louis Gore-Langton
