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Tough science ahead in oxo-bio plastics debate

What has driven Michael Gove’s sudden obsession with plastic? He became environment secretary only in June 2017, having previously been education secretary and never having shown much engagement with environmental issues – although he did get into a fight with then energy secretary Ed Davey, who objected to Gove downgrading cli­mate change in the national curricu­lum.

Yet in the space of a month, Gove has announced a deposit return scheme for drinks containers, had kind words for a potential enzyme that eats plastic as its favoured diet and lined up with pro­ponents of the controversial oxo-biode­gradable approach to dealing with plastics waste. Its fans say this breaks down plastic into material that can be consumed by nature.

One reason for the secretary of state’s sudden enthusiasm may be a height­ened public awareness of plastics pollu­tion, in particular in the world’s oceans, where television documentaries show­ing waste plastic in improbable marine settings have driven concern that this pollution should be stopped.

When the public takes up such an issue, politicians can get into a cycle of thinking that “something must be done, this is something, so let’s do it”.

So Gove appeared on the BBC’s One Show – not the foremost arena for sci­entific debate – to declare that he had asked the Government’s chief scientific adviser to tell him whether there was anything in oxo-biodegradables as a means of controlling plastics pollution.

Simon Ellin, chief executive of the Recycling Association, said: “It’s the nature of politics – recycling and plas­tics in particular are in vogue and have captured public attention. So that becomes political and, ultimately, becomes votes so there is an element of that in Gove’s interest.

“I welcome him being more inter­ested in recycling, whatever his motive.”

Gove’s intervention came only a few days after senior figures from Sym­phony Environmental – one of the main manufacturers of oxo-biodegradables – had addressed a seminar on the sub­ject at London’s Commonwealth heads of government meeting.

Clearly the pro-oxo people are no slouches at political lobbying. But until Gove’s statement, they had been on the back foot with both the European Par­liament and the influential Ellen MacArthur Foundation set firmly against the technique.

But the oxo industry has secured sup­port from prominent naturalist Chris Packham, who appeared on TV along­side Gove when the secretary of state said: “I’ve been talking to companies that have an interest in this area and I have got the chief scientific adviser to look at the science behind it.

“Evidence overwhelmingly suggests that oxo-plastics do not achieve what their producers claim and instead contribute to microplastic pollution.”

“It’s a potentially exciting develop­ment. But we need to be certain, actu­ally, that if we are going to put public money behind some of these schemes, that we’re absolutely confident we deliver the results that the inventors and the entrepreneurs behind them are so anxious to deliver.”

Gove did not say with what urgency anyone would “have a look” but, as a prominent Brexiteer, he may also have seen the opportunity to annoy the Euro­pean Commission. It has “had a look” at oxo-biodegradables and did not like what it saw.

In January, the Commission said it would take steps to restrict the use of oxo-biodegradable plastics across the EU, having warned during the same month in its plastics strategy that bio­degradable and compostable plastics of all kinds could lead to greater littering and compromise recycled material streams unless they were clearly labelled.

It said at the time: “As regards so-called oxo-biodegradable plastics, there is no evidence that they offer any advantages over conventional plas­tics. They do not biodegrade and their fragmentation into microplastics causes concern. Taking into account these con­cerns, the Commission will start work to restrict the use of oxo-plastics across the EU.”

Concerns about oxo-biodegradables boil down to two issues: that they do not really degrade and so cause as much marine pollution as any other sort of plastic; and that if they infiltrate the normal plastics recycling stream they will contaminate entire batches.

As Ellin commented: “My fear is that oxo breaks down into microplastics and that can then give you an even bigger problem. As I understand it, equipment in MRFs cannot distinguish oxo from a normal polymer, so you could find it gets into products made from recyclable material then starts degrading. But we do need more scientific research.”

The Ellen MacArthur Foundation has not changed its stance since it issued a report last November, which argued that, while the public was being led to believe that oxo-biodegradable plastics safely degraded in nature, “significant evidence suggests oxo-degradable plastics…fragment into small pieces, contributing to microplas­tics pollution”.

It recruited 150 organisations includ­ing Marks & Spencer, Unilever, Veolia and the British Plastics Federation Recycling Group to sign a statement against oxo-biodegradables.

Rob Opsomer, the foundation’s lead officer for systemic initiatives, said: “The available evidence overwhelm­ingly suggests that oxo-degradable plastics do not achieve what their pro­ducers claim and instead contribute to microplastic pollution. In addition, these materials are not suited for effec­tive long-term reuse, recycling at scale or composting, meaning they cannot be part of a circular economy.”

But what is the ‘available evidence’ used by the foundation? As with any unsettled scientific question, there are voices on both sides claiming that science incontestably shows they are right and their opponents wrong, and oxo-biodegradables are no exception.

One would need a chemistry degree – probably several – to understand the fine details of differing views of the abil­ity of these materials to harmlessly degrade. Symphony’s deputy chairman Michael Stephen unsurprisingly believes they can and do.

He told MRW: “I think the Govern­ment has realised that something has to be done and is aware of public con­cern. It is all very well talking about the reuse and recycling of plastic, but if it is already in the ocean you cannot do that.

“Oxo can be recycled whereas plant-based plastics cannot. The recycling industry has nothing to worry about. If you take an oxo product to a recycling centre, they have ways of separating it from other plastics.”

Stephen added that he thought the European Commission had been excessively influenced by the MacArthur report, whose scientific validity he questioned. He pointed out that oxo-plastics are now mandated in Paki­stan, Saudi Arabia and the United Arab Emirates.

Symphony has backed up its political offensive with the results of a YouGov survey that it commissioned among 2,017 UK residents. This found that 86% of respondents would be happy to use oxo-biodegradable plastic instead of their usual plastic, 90% would support treating everyday plastic items with oxo-biodegradable technology and 88% would support the UK making the use of oxo-biodegradable plastics a legal requirement.

Some support for this optimism came in March from US market research firm Persistence, which said in a report that expansion of the oxo-bio­degradable plastic packaging market into the Middle East was “a potential growth opportunity”.

It added: “Countries such as the UAE and Saudi Arabia have made it mandatory to use plastics that are oxo-bio­degradable. This has made it imperative for trading companies to switch towards oxo-bio plastic packaging solutions while dealing with [the] Middle East and Africa region, and thus has pre­sented high growth opportunities for the oxo-bio packaging market.”

Persistence said that although some large plastics manufacturers had pro­tested against the use of oxo-biodegrad­ables for packaging, smaller firms had found that they “appealed to a signifi­cant percentage of consumers who are conscious regarding environment health”.

The report noted that ‘oxo-biode­gradable’ had moved from being a tech­nical term to one used prominently in marketing, and concluded that the global market for oxo-bio packaging was poised to expand at 5.4% during 2018-26, by which time global sales would exceed $1bn.

Both the European Commission and the Ellen MacArthur Foundation remain unimpressed, but Gove is open to persuasion.

Who is right will depend on scientific research that few people can grasp. But on that will turn whether this market lifts off or remains out of the main­stream.

Enzymes prefer pet for lunch

An accidental discovery at the University of Portsmouth has yielded an enzyme which can digest plastics made of polyethylene terephthalate (PET).

Professor John McGeehan worked with the US National Renewable Energy Laboratory to study the enzyme. During the process the team “inadvertently engineered an enzyme that is even better at degrading the plastic than the one that evolved in nature”, the university says.

Their breakthrough came when they examined an enzyme thought to have evolved in a waste recycling centre in Japan, allowing a bacterium to degrade plastic as a food source. Researchers are now working on ways to further improve the enzyme so it can be used industrially to break down plastics.

McGeehan said: “Few could have predicted that since plastics became popular in the 1960s, huge plastic waste patches would be found floating in oceans or washed up on once-pristine beaches all over the world.

“We can all play a significant part in dealing with the plastic problem. But the scientific community that ultimately created these ‘wonder-materials’ must now use all the technology at their disposal to develop real solutions.”

Readers' comments (1)

  • In case you've missed it, a restriction dossier is currently being developed for oxy-degradable plastics (due to be submitted to ECHA Jan 2019).

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