Recycling

To listen to a discussion on the recycling of oxo-biodegradable plastic – click on the audio below.

PLASTIC IN THE ENVIRONMENT

For many years the oil companies and plastic manufacturers have been warned by governments and NGOs that their business is under threat because plastic creates microplastics and is very persistent in the environment.

“Redesign, reduce, re-use, recycling” are all very well, but after 20 years or more the problem of plastic in the environment is still getting worse, and very few governments around the world have any policy for dealing with the plastic which does NOT get collected for recycling. They could require the plastic to be oxo-biodegradable (as governments in the Middle East have already done) but most of them simply cling to the unrealistic hope that they can do without plastic, or can collect all of it for recycling.

A better option is for governments to require that a pro-oxidant masterbatch such as d2w be used in the manufacture of all short-life polyethylene (PE) and polypropylene (PP) products, so as to make them biodegradable at the end of their useful life. They will not then lie or float around for decades if they escape into the environment, but governments who fail to do this are responsible for the continued accumulation of plastic in the environment.

THE RECYCLING INDUSTRY

There is confusion in this industry about biodegradable plastic. Despite the urgent need to tackle the problem of plastic accumulating in the environment, there are still some in the industry who are reluctant to accept it, thinking that it could adversely affect the new plastic products made with their recyclate. “Recyclate” means flakes or granules of polymer made by reprocessing existing polymer products, and which are then used to make new polymer products.

It is necessary therefore to consider whether this reluctance is justified, and whether recyclers are right to support the continued use of ordinary plastic, which can be recycled if collected but will not biodegrade for many decades if it gets into the open environment.

CAN BIODEGRADABLE PLASTICS BE RECYCLED?

Yes, and no.

Yes – Oxo-biodegradable plastic is made as to 99.9% from the same material as ordinary plastic. Oxo-biodegradable plastic films have been tested at specialist laboratories in Austria and South Africa and have been found to be recyclable without separation. Also, plastic bottles made with an oxo-biodegradable masterbatch have been tested by AIMPLAS according to the Critical Guidance Protocol for HDPE Rigid Containers ( HDPE-CG-01) published by the Association of Plastics Recyclers of the USA and were found to be recyclable without any need for separation from ordinary polyethylene (PE) and polypropylene (PP).

No – the type of bio-based plastic marketed as “compostable” has a fundamentally different chemistry to ordinary (petroleum-based) plastic. It is intended to be sent to an industrial composting facility where it will convert into CO2, but if even a small proportion of this type of plastic gets into a post-consumer recycling stream it will compromise the resulting recyclate and damage the new product made with it.

In this paper we will consider:

Whether oxo-biodegradable plastic products are likely to be recycled at all
If so, into what type of new product
Whether they are likely to have any adverse effect on the new product.

LIKELY TO BE RECYLED AT ALL?

Oxo-biodegradable technology is used in PE and PP only, and is used mostly for packaging films and other low-value film products which at the end of their useful life are often contaminated with biological contaminants and mixed with other household waste. Plastic films are not generally recycled in the US, so there should be no problem with those products.

Plastic bottles made of P.E.T. are worth recycling, but oxo-biodegradability is not an issue here because it is not used in P.E.T. Plastic bottles can be made with PE.

Whilst almost all pre-consumer waste PE and PP (eg factory offcuts, the provenance of which is known) is recycled, most of the post-consumer PE and PP products are not.

There is a very good video which explains why recycling of post-consumer plastic makes very little sense in economic or environmental terms.

An investigation by ABC News showed that most of the short-life plastic products collected for recycling in the USA do not get recycled and are instead landfilled or incinerated.

Greenpeace reported in October 2022 that “mechanical and chemical recycling of plastic waste fails because plastic waste is extremely difficult to collect, virtually impossible to sort for recycling, environmentally harmful to reprocess, often made of and contaminated by toxic materials, and not economical to recycle.”

Recycling is also a source of microplastics. A report in the Journal of Hazardous Materials says “Raw recycling wash water was estimated to contain microplastic counts between 5.97 106 – 1.12 × 108 MP m−3 (following fluorescence microscopy analysis). … Microplastics <5µm were generally not removed by the filtration and subsequently discharged, with 59-1184 tonnes potentially discharged annually.”

According to the Los Angeles Times (Aug 24^th 2023) recyclers do not want plastic bags. “They wind themselves around the idlers and pulleys of the conveyor belts, jam the bed knives in the shredders, get tangled in the shafts of the disc screens and snarl the parallel paddles of the ballistic separators.”

“If you vacuumed up a plastic bag into a recycling process, you’d probably have to take apart the whole machine to fix it. That’s what happens in recycling centres. The one in Burbank has to clear plastic bags from screens four times every day, on two dedicated 10-minute breaks and again for 30 minutes at lunch and at the end of the day. Phoenix’s city recycling centre estimates it loses $1 million a year on bag extraction.”

A report by Kinnaman et al (68 Journal of Environmental Economics and Management (2014) 54-70), evaluated the cost of recycling each material, the energy and emissions involved in recycling, and various benefits (including simply feeling good about doing something believed to have an environmental or social benefit). They came to the conclusion that an optimal recycling rate in most countries would be around 10% of goods. “To get the most benefit with the least cost, we should be recycling more of some items and less — or even none — of others. The composition of that 10% should contain primarily aluminium, other metals and some forms of paper, notably cardboard and other source[s] of fibre, while optimal rates of recycling plastic might be zero.”

The UK recycling charity RECOUP says (in their publication “Recyclability by Design”) that “where plastic products are particularly lightweight and contaminated with other materials, the energy and resources used in a recycling process may be more than those required for producing new plastics. In such cases recycling may not be the most environmentally sound option.” These are the very products for which d2w is designed.

Another reason why postconsumer plastic is not popular with recyclers is that it has to be separated from other household waste and from other types of plastic, and then washed. A lot of water is needed to wash contaminated plastic, so the amount of waste-water generated is enormous, and in many countries water is a scarce resource in part or all of the year. Moreover, this process leaves large quantities of dirty waste, including biological and chemical waste that is hazardous and highly undesirable.

At the end of its useful life, plastic which has been collected but is not suitable for recycling, should not be wasted by being sent to landfill. It should revert to being a fuel, and be sent to modern incinerators to be used for generating heat and electricity instead of importing more oil and gas. Modern incinerators like the one in the city of Zurich, do not cause harmful emissions.

WHAT TYPE OF NEW PRODUCT would oxo-biodegradable plastic be used to make?

No recycled polymer can ever achieve 100% of the properties of virgin polymer. This is because the physical properties (tensile strength, resistance to chemicals, etc.) are adversely affected by the recycling process.

The use of recycled plastic is not normally permitted for food-packaging, or pressure-piping, and is strictly limited in the case of building films, so these are not relevant products.

Recyclate from PE or PP would not be mixed with recyclate from PET, and would not therefore be used to make synthetic fibres for carpets, geotextiles, or clothing. As already noted PET products would not be oxo-biodegradable.

In summary an oxo-biodegradable plastic product can be recycled if collected, but these products are not usually recycled at all.

NO ADVERSE EFFECT on new products made with recyclate which contains oxo-biodegradable plastic.

The PE and PP plastic for which oxo-biodegradable technology is used, is likely to be recycled (if recycled at all) into packaging, and similar low-value items which often get into the environment as litter.

The scientist who wrote the Roediger Report 21^st May 2012 says “If the new product, to be made from recyclate containing [oxo-biodegradable masterbatch], is intended for short-life uses such as garbage-sacks, bin-liners, shopping bags, bread-wrappers etc. the effect of any pro-oxidant formulation is unlikely to manifest itself before the end of the intended service-life. Biodegradability for such items is in any event desirable, because a proportion of them will find their way into the land or sea environments, where they could otherwise subsist for decades after being discarded.”

It is however possible that some PE or PP recyclate which contains some oxo-biodegradable PE or PP might be used to make durable PE or PP products such as blow-moulded components for the automotive industry, or drainage pipes. Here, it is important to note that chemical stabilisation is the key to durability of all plastics, whether they contain an oxo-biodegradable masterbatch or not.

Conventional plastics may contain pro-oxidant additives that were added to produce different intended functionalities. For example, Moura et al. (“Dyes and Pigments” Vol. 33, No. 3, pp. 173 196, 1997) showed that colorants in general can act as pro-oxidants. If they partake in the creation of radicals or reactive oxygen species, such as singlet oxygen (1Δg), they can trigger photo-degradation of the polymer matrix. Conventional plastic products have been found to regularly contain iron, barium, titanium, zinc, copper, and vanadium.

The point of this is that it cannot be assumed by manufacturers of polymer products that any recyclate is free from pro-oxidants, whether it contains biodegradable plastic or not. It is therefore always necessary to add stabilisers when making long-life plastic products.

STABILISERS

The Roediger report from South Africa says “With regard to long-life products, since polymers lose stabilisation each time they are reprocessed, it is good practice when making long-life products from recycled polymer to add stabilisers, whether the feedstock contains plastic with pro-oxidant masterbatch or not.”

The TCKT Report of 27^th July 2016 from Austria says “… the UV stabiliser inhibits the propagation of free-radicals which are responsible for polymer degradation. Stabilised samples therefore exhibit a smooth, un-cracked and uninfluenced surface.”

The Roediger report adds “The stabilisers will neutralise any pro-oxidant which may be present. However, as the recycler does not usually determine the final use of the recyclate, the stabilisers would be added by the next processor in the chain – the manufacturer of the new finished product.”

Roediger continues “The specification in some countries for long-life building films requires the use of a virgin polyolefin, and recyclate is not therefore used at all for these products. In the case of lower-grade building films, where no guarantee is given, these are sometimes made from recyclate whose origin is not known, but the manufacturer of the film would always add stabilisers, whether the feedstock is known to contain a pro-oxidant formulation or not.”

It is important to note that it is not necessary to use stabilisers which are any different to the ones which would normally be used for conventional PE or PP, nor to add a different quantity of the stabilisers. Nor is it necessary to estimate the proportion of stabilisers already added.

The extent of degradation already present in the material must be assessed before reprocessing, whether the feedstock contains oxo-biodegradable plastic or not, as any plastic which has been exposed to sunlight for a significant length of time may no longer be suitable for recycling.

A Report by Aldas et al is sometimes cited in support of the proposition that degraded oxo-biodegradable plastic will have an adverse effect on products made with recyclate. This is not a useful proposition, because degraded plastic should not be used for recycling whether it is oxo-biodegradable or not.

Also the Aldas authors were incorrect in adding d2w masterbatch @5%. This is five times the amount specified by the manufacturers, Symphony Environmental.

The Aldas report shows (at 2.2.4) that degraded oxo-biodegradable plastic was incorporated into the neat (i.e. non-oxo) LDPE. They predicted an adverse effect on the new product made with this recyclate, but they did not examine the effect of incorporating degraded plastic without d2w, on new products made with recyclate. Had they done so they would have found a similar adverse effect on the new product.

The same fallacy is evident in footnote 15 of the 2019 Ellen MacArthur Report, that “both the heat and UV ageing tests were performed on samples that were ‘recycled’ (blown into film and then re-pelletised) in-house from primary materials rather than from recovered post-consumer waste material. Therefore, this does not demonstrate the effects of any oxidation as a result of UV ageing that has occurred during use, and/or between disposal and being recycled as in real world environments.” If significant oxidation has occurred in any plastic it should not be recycled, and recyclers being aware of this always add stabilisers.

Oxo-biodegradable plastic products are stabilised to allow for a storage and service-life, and to allow time for re-use and recycling. The TCKT study found that unstabilised plastics made with recyclate with and without pro-oxidant masterbatch, both failed rapidly during sunlight exposure; but the stabilisers, routinely used in the manufacture of long-life products, were successful in preserving the products with and without the masterbatch. These would include for example blow-moulded parts used in automotive applications.

The authors of the Aldas report are not correct in saying that “for these types of plastics to be considered as biodegradable, their biodegradation must be no less than 90% after the assimilation time limits have elapsed according to the European standard EN13432.” This standard does not apply to oxo-biodegradable plastics – which are designed to degrade if they become litter in the open environment. EN13432 itself says in para 1 that it “makes provision for obtaining information on the processing of packaging in controlled waste treatment plants, but does not take into account packaging waste which may end up in the environment through uncontrolled means, ie as litter.”

The authors of the Austrian TCKT Report (March 2016) say “In our opinion it is unlikely that recyclate from short-life films would be used for long-lasting films used in the building industry. These long-life films should be made with virgin polymer and be stabilized to deal with loss of properties caused by the melt-processing and the recycling process, whether or not any pro-oxidant additive is present. Such stabilization would effectively neutralize the effect of any pro-oxidant additive.”

It is always important to compare the performance of PE and PP containing oxo-biodegradable masterbatch with the conventional PE and PP found in a post-consumer recycling stream, and not with some hypothetical material which does not degrade. It is also important not to confuse these polymers with PET.

It is essential that products made wholly or partly from recyclate containing pro-oxidant masterbatch are not expected to pass tests which products made from conventional plastic recyclate would fail under the same conditions.

An unrealistic scenario is as follows: “A bottle made with oxo-biodegradable masterbatch makes it through the recycling collection stream and ends up in a bale of crushed PET bottles. The bale sits outside for several weeks exposed to sun and weather, and then goes through the normal grinding, washing, and pelletizing process of recycling.

The recycled PET plastic is then made into strapping that holds bricks on a pallet. The pallet is stored outside for many months because bricks are insensitive to weather. Then the pallet is placed on the back of a truck heading down the highway. That’s a lot of time, weather, and heat that could potentially trigger the degradable qualities of the plastic with additives present and cause that strapping to fail. The consequences could be very serious.”

There are three fundamental mistakes here:

Pro-oxidant masterbatches are not used in the manufacture of PET bottles.
The exposure to sun and weather before recycling described in this scenario is likely to impact adversely on the suitability of the plastic for recycling whether it contained a pro-oxidant masterbatch or not. In any event sunlight would reach only the exposed surfaces, not the interior of the bale, and as plastic feedstock is valuable to recyclers they would be likely to protect the bales from sunlight.
The conditions of use described in this scenario would make it essential to have included stabilisers to protect plastic strapping against time, weather, and heat, whether the recyclate contained a pro-oxidant masterbatch or not.

In a follow-up to their report TCKT reported in July 2016 on the potential for recyclate containing oxo-biodegradable plastic to be used in long-term outdoor applications in thick cross-section products such as garden furniture or plastic lumber. They observed that “as degradation is dependent upon oxygen, the thickness of the material limits the penetration of oxygen into the body of the plastic. Therefore, the thicker the material, the less susceptible to degradation it will be. Evaluation of the FTIR-spectra confirms that inside the sample, where oxygen is not available, no significant oxidation has been found in any of the samples.”

They added “an important point to remember is that thick cross-section plastic products intended for use outdoors should always contain a UV stabiliser whether or not they contain any recyclate with a pro-oxidant masterbatch. The stabiliser is there to protect the products from the damaging effects of sunlight and more general weathering influences, because they would not otherwise be fit for purpose.”

“The UV stabiliser inhibits the propagation of free-radicals which are responsible for polymer degradation. Both stabilised samples (with and without pro-oxidant masterbatch) exhibited a smooth, un-cracked and uninfluenced surface.”

They added “We have chosen the worst-case scenario by using samples made entirely from recycled polymer material, which is very unlikely in practice. In reality it is likely that recyclate would be mixed with virgin polymer, and the material containing a pro-oxidant masterbatch is therefore likely to contribute part only of the overall recycled material.”

“The catalytic activity of stearates is not linear to their concentration. It is an asymptotic curve so, due to dilution with polymers which do not contain the catalyst, the stearates stop catalysing the degradation reaction due to an insufficient concentration.”

It is said that “testing of tensile properties is useful but incomplete, and the two more important tests are flexural properties and impact properties. Materials with surface defects are prone to failure when loaded in flexure, and embrittled materials are prone to fail in impact testing.”

These tests may be used to assess the quality of products containing conventional and/or oxo-biodegradable recyclate, but verification of polymer stability is best done by measuring oxidation of the polymer directly, as a proxy for molecular weight reduction – which is the root cause of loss of mechanical properties. These plastics are tested for thermo-oxidation, which will detect changes long before changes occur in their appearance or mechanical properties.

It is also said that testing recognizes ageing of the final product, but in recycling there is also the ageing of the initial product to consider. However, as already noted, polymers exposed to sunlight and air for extended periods are likely to experience oxidation, whether or not they contain a pro-oxidant masterbatch, and in both cases there will be a point in time when they are no longer suitable for recycling. In fact, real-time outdoor ageing of d2w oxo-biodegradable plastic and a conventional plastic control, identified that the onset of oxidative degradation (representing the point at which the plastic is no longer suitable for recycling) occurred on the same day as the conventional plastic (Bandol 2015, 2016).

In March 2016 TCKT of Austria recycled a sample of LDPE film containing Symphony’s d2w, and found that “not only did the film made from the recyclate retain thermal stability after reprocessing, but the impact of the stabiliser in the masterbatch itself was greater than the effect of the pro-oxidant in the masterbatch – resulting in stability which actually increased with the proportion of recyclate containing d2w masterbatch.”

The characteristic of the plastic containing the pro-oxidant masterbatch was not that it became unsuitable for recycling earlier, but that subsequent degradation progressed more rapidly, even in the absence of sunlight or heat, until the plastic became biodegradable.

Products made with oxo-biodegradable technology from aged material are evaluated for thermo-oxidation due to ageing, in order to ensure that the product is fit for initial use (shelf/service life/ reuse) and to allow sufficient time for collection for proper disposal, including recycling. All such validated products show adequate stability, which is predicted using very conservative factors and modelled for extreme storage conditions. This is expected to substantially underestimate the actual shelf and service life of the products.

In fact, as already noted, the stabilisers in the masterbatch can result in increased stability during shelf and service-life, as compared with the same PE or PP product made without d2w masterbatch.

Again, the TCKT (July 2016) study found that oxidation of both conventional and oxo-biodegradable products was eliminated by the use in each case of the UV stabilisers which would always be used for products intended for long-term use.

It is also said that “The nature of plastics-recycling is that initial products are not exclusively directed to specific end-uses. Films do go back into films but also go into thick-sectioned items such as plastic lumber. This means that test protocols need to call for the most challenging use comparison, not the least.”

This is well understood, and it is the manufacturer of the new product, not the recycler, who decides what recyclate to use for which products, and what stabilisation to add.

The TCKT studies (March and July 2016) examined recycling of inherently low-stability LDPE films (as a worst-case scenario) into both short-life film and durable thick-cross section products – demonstrating that satisfactory products can be produced and that in both cases the contribution of stabilisers in the masterbatch itself has a more significant impact than the pro-oxidant catalyst in the masterbatch.

It is also said that “Accelerated ageing for complex systems is relatively easy to conduct, but not so easy to interpret. For actions that are described by first order kinetics, a linear log(time) relationship is well known. When there are multiple steps involved with the limiting steps changing over time, converting hours in a weather-o-meter to actual exposure time is rather uncertain. And, when the next use of the recycled plastic can be for years of service, the accelerated aging must be validated to assure the testing on accelerated aged specimens have useful meaning.”

However, most ordinary waste plastics will have been exposed to UV radiation, in particular agricultural film, and may have oxidised to some extent, but not enough to become biodegradable. Recyclers of mixed plastic wastes have no way of knowing which have been exposed and for how long, and it is also known that printing inks, and other chemicals will affect the recycling process. Therefore, the industry already has the problem of identification when dealing with post-consumer plastic films, and deals with it by using those materials for low-value/short-life applications such as carrier bags and garbage sacks, and also by adding stabilisers where necessary.

It is true that photo-oxidation in the environment is difficult to model, but since it is well known that sunlight causes damage which is likely to harm the recyclability of the plastic, feedstock should not be collected for recycling and stored in sunlight for extended periods. For so long as it remains suitable for recycling, and if the next use of the recycled plastic is for durable products, it should of course be stabilised as already mentioned.

Stability to thermo-oxidation is the critical parameter for processing and long-term storage of polymer recyclate; and is much better understood and simpler to model. Therefore shelf-life and service-life prediction for polymers via well-established principles, (including those included in ASTM F1980), is typically done with conservative factors in order to provide a substantial margin for error.

There is also the question of dilution. Pro-oxidant catalysts are incorporated in the masterbatch at trace levels and dilution is likely to result in a degradation response which is indistinguishable from the degradation behaviour of conventional polymers. We have already noted that conventional PE and PP contain compositional and structural impurities.

It is also said that “In the practical world the recyclers have no reasonable means of knowing if a pro-oxidant is present. The variety and concentration levels are not helpful to detection and the economics of such a sorting would not be trivial.” Again, this is well understood, but separation of different types of polymer is a problem with all types of plastic product, and is one reason why post-consumer plastic film is not attractive to recyclers. However, as we have explained, sorting of PE and PP products containing pro-oxidant masterbatch from PE and PP products without such masterbatch, is not necessary.

Nor in the practical world do the recyclers always know to what conditions and for how long the conventional polymer feedstock coming to their facility for recycling has been exposed. Moreover, as we have seen, any conventional PE or PP received for recycling is likely contain an unknown quantity of compositional (catalyst residues, mineral pigments, etc) or structural (carbonyl and peroxide groups, vinyl content, etc.) impurities that act in the same way as pro-oxidant masterbatches to cause degradation to occur (Yousif 2013). One cannot therefore accept the simple proposition that conventional plastic can be safely recycled and d2w plastic cannot.

The processing of plastics which may contain pro-oxidant masterbatch must therefore be managed in the same way as any other post-consumer plastics, and it is not necessary to determine the presence or level of pro-oxidant masterbatch. Instead, if long term stability of new products is critical, the manufacturer of the new products will make a performance-based evaluation for the type of product he wishes to make, and determination of oxidation and mechanical properties, with or without accelerated ageing – this is critical as much for conventional recyclate, as for recyclate which contains or might contain pro-oxidant masterbatch.

One recycler has said “Will degradable additives in plastics help the environment? It is hard to see how that can be. Fragmenting plastics such as created by oxo-degradable additives has few if any benefits and many potential problems. Degrading plastics to methane may sound good, but the capture rate of methane in landfills is such that the biodegradable additives may increase greenhouse gas emissions.”

The recycler was mistaken here. Plastics containing pro-oxidant masterbatches such as d2w do not simply cause the plastic to fragment (this is what happens to ordinary plastic under the influence of sunlight). They rapidly reduce the molecular weight after the stabiliser is exhausted at the end of the designed life of the product, so that it becomes a waxy material which is no longer a plastic and is biodegradable.

As Intertek said in their evidence to the European Chemicals Agency, the benefits of degradation are obvious, because conventional plastics, of which recyclers approve, will accumulate in the environment for decades – do recyclers think that all the plastic litter gets collected? If so, why is there so much public concern about plastic in the environment?

The same recycler also said “A degraded plastic material is an opportunity lost to reuse a valuable resource through recycling which provides tangible benefits in reducing greenhouse gases and energy use compared to use of virgin plastics.” However, recycling of plastics is a significant user of energy and emitter of CO2 and it is questionable whether recycling reduces greenhouse gases and energy use compared to the use of virgin plastics.

In any event, oxo-biodegradability is intended for plastic which cannot be recycled because it has escaped into the open environment from which it cannot realistically be collected. The opportunity has therefore been lost, not because the plastic is biodegradable, but because waste-management has failed and the material has not been collected in time or at all.

It has been observed that “due to the emerging nature of the degradable additive technologies, these materials are not currently part of the recyclers’ recognition programs.” However, the technology is not emerging – it has been commercially available for more than 30 years, and this type of plastic has even been mandatory in some parts of the world – e.g. in the UAE since 2009, and Saudi Arabia since 2018.

Notwithstanding all this, on 5th September 2024 the Association of Plastic Recyclers in the US issued a statement saying “A package including Degradable Additives, Nutrients, or Supplements cannot be detected using commercially available technologies and will affect both the quality and yield of post-consumer recycled resin (PCR) when they perform as designed.”

This is an anti-competitive statement aimed at a small US company called BioBottles trying to introduce a biodegradable HDPE bottle for Nutrients and Supplements. This bottle is made with a d2w masterbatch and will not therefore lie or float around for decades if it gets into the environment.

It may or may not be correct that a package including Degradable Additives, Nutrients, or Supplements cannot be detected using technologies commercially available to recyclers, but it would be easy for masterbatch producers to include a tracer. This is not however necessary because products made with a d2w masterbatch can be safely recycled, for the reasons already given. By contrast, plastics certified as “compostable” cannot be safely recycled but are still being sold.

Also, how can nutrients or supplements have the slightest relevance? They are the products packed within the bottles, so you might as well say that marmalade is incompatible with recycling.

Evidence that the people at APR have no real understanding of oxo-biodegradable technology is the fact that they expect the residue of the bottle after the Tier 1 test in ASTM D6954 to be tested for recyclability. Anyone with an understanding of polymer science would know that a bottle whose molecular weight had reduced to 5,000 or thereabouts (in accordance with para. 6.3 of D6954) could not be collected for recycling, because it would have lost all its tensile strength and be no longer a plastic.

APR asked Berry Global to support their statement by saying that “the most effective solution to plastic waste is to design products for recycling and reuse, incorporating recycled content.” All well and good, but they are ignoring the plastic waste that gets out into the open environment and cannot be collected for recycling or anything else, and it is that fraction of waste which is causing so much public concern. After more than 20 years it is now clear that “Redesign, Reduce, Re-use, and Recycle” is not working and the problem is getting worse. Oxo-biodegradable technology has been designed to deal with it, by making it biodegrade much more quickly, leaving no microplastics behind.

APR also cite the US Plastics Pact in support, but we are not impressed by their lack of understanding of polymer science.

This attack by APR will not only damage the environment, but will damage the recyclers themselves. Campaigns against plastic are based primarily on its persistence in the environment, and these campaigns are reducing demand for plastic recyclate and reducing availability of plastic feedstock for recyclers.

CONCLUSION

Both of the TCKT studies from Austria, and the Report by Roediger Laboratories in South Africa have been available to recyclers for years on the websites of Symphony Environmental and the Biodegradable Plastics Association. All of these studies demonstrate that recycling of oxo-biodegradable plastics can be safely achieved up to 100% inclusion of oxo-biodegradable plastics, but the proportion of these plastics in a post-consumer waste stream would be much lower than that.

It is essential to make plastic in future so that it will biodegrade if it gets into the open environment without any human intervention.

Eco II Manufacturing Inc, one of the largest manufacturers of garbage bags in Canada, say “We include oxo-biodegradable LDPE in the feedstock for recycled material which we use for both oxo-biodegradable and conventional plastic bags, and we have never had any problems in the recycling or manufacturing processes, nor have we received any complaints of premature degradation of the conventional or oxo-bio garbage bags.”

The author of the Roediger Report said “We are able to confirm that plastic products made with oxo-biodegradable technology may be recycled without any significant detriment to the newly formed recycled product.”

In the last 15 years, enough masterbatch has been sold by Symphony Environmental alone to make more than 2 million tonnes of biodegradable products from polyethylene and polypropylene, and it is used by the largest bread manufacturer in the world for their bread packaging. We know that these products have been successfully recycled around the world, and in those 15 years we have heard no reports of any difficulty encountered. Our experience is entirely consistent with the specialist reports mentioned above, that oxo-biodegradable plastic can be safely recycled without separation from conventional plastic.

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