Plastic packaging

What you can do: 

  1. Suggest to your favorite coffee house that they use biodegradable coffee cups
  2. Lobby government to require all crisp packets, sweetie wrappers, takeaway containers to be paper or biodegradable plastic
  3. Push for deposits to be put on all drinks containers

The coffee cup furore shines a spotlight on the whole food and dry goods packaging industry. The main culprit is oil based plastic. Plastic packaging is alien to our environment but does such a good job preserving perishable food. What is to be done?

Disposable coffee cups have a plastic liner, which stops the coffee seeping out. Were the plastic unnecessary and the cup purely paper, it could either be recycled after use for paper making, sent to a composing unit or, if discarded at the roadside, will quickly decompose.

Oil based plastics

Oil based plastics are incompatible with our ecosystem. They are made of long chain molecules which cannot be digested by soil based microorganisms. Natural organic materials are biodegradable; wood, paper, cardboard, fruit, vegetables, meat, bones, nuts, all decompose to either a crumb compost material or a bacterial slime. This natural decay is part of a cycle where old growth breaks down to feed new. We put compost and dung on our vegetable patches to feed the next crop. In contrast, plastic released into nature remains unchanged.

Biodegradable plastics

Coffee cup, lid and sugar sachet, all compostable

What we need are packaging materials that have the same moisture retaining properties of oil based plastics, but which compost down in nature if discarded as litter. Biodegradable  plastics have been around for over 20 years. They are made from maize, potatoes, molasses, etc., all-natural substrates. These are digestible by soil borne organisms, so break down when in contact with soil, or other organic material. Provided they meet the EU standard of EN13432, they will break down by 90% in 90 days. Biodegradable plastics can be translucent or opaque. After use as packaging, they can be disposed of in the food compost caddy or garden waste wheelie bin. They are however more expensive than oil based plastics.

Strategy for plastic packaging

A simple strategy can solve this environmental issue, but needs the government to act. The strategy would state that:

  • Oil based plastic bottles must all have deposits on them
  • Other food and dry goods packaging exiting through the retailer door must be biodegradable

Survey data (Warmer Bulletin, 2002) exists to show that bottle recycling exceeds 90%, if the bottles have deposits on them. Litter is reduced as any bottles lying around give scavengers an income.

Retailers can use any oil based plastics they like in their supply chain, so long as they return them for reuse or for recycling through their supply chain. Much packaging already returns in the virtually empty lorries returning for the next delivery. However, items for sale such as fruit and vegetable containers, meat boxes, bakery containers, crisp packets, confectionary, all must be biodegradable. This will ensure that any litter created by these items rapidly breaks down in contact with the soil.

Surely we can burn oil based plastics?

Increasingly the waste management industry sees burning as the answer to difficult-to- recycle waste plastics, contaminated paper and cardboard. If all waste collected, this would be one solution; but it is not. Therefore, potential wastes must be biodegradable. This does not rule out burning as a waste disposal option, but it will reduce litter.

Understanding oil-based plastics

Oil-based plastics are man made polymers, numbered 1-7, with differing properties which suit different purposes. PET, No 1, is used for drinks bottles, HTPE, No 2, is used for shampoo bottles and so on. These polymers all have different melting points, so are largely incompatible when it comes to recycling and reprocessing. They must therefore be separated before being reprocessed. While bottles are worth recycling, the films which cover much of our fruit and prepared meats are not. They often have a label “not currently recycled”.

To you and I these films look like plain polythene (LDPE, No 4). Some are, but some are not. While all films hold water, they differ in the rate that they allow oxygen and carbon dioxide gases to pass through. This makes them suitable for use in modified atmosphere packaging, where fruit like strawberries, living organisms like ourselves, create a high carbon dioxide (CO2) atmosphere within the pack. This reduces their rate of decay and so extends their shelf life. To achieve the correct permeability for the CO2 and oxygen, two or more laminates of different polymers may be used. This makes them almost impossible to recycle. In addition, their flimsy nature makes them more trouble to recycle than they are worth. So, “not ever likely to be recycled” should perhaps be on the label.

Strong dye needed to obtain a uniform colour. What happens when these bags are recycled?

The last aspect of oil-based plastic recycling is colour. Plastics must be separated into their different colours. Since these colours vary in shade, the final product must have a strong dye added to produce a standard product. The question is what to do with this plastic the next time round.

Plastics for preservation 

Plastic packaging has two great advantages over paper. It prevents moisture loss, keeping fruit and vegetables firm and bakeries soft and fresh. It can also be made translucent, so customers can see the contents within the pack. Biodegradable plastics can do the same job.  Work on biodegradable packaging for modified packaging is well developed. One complication is the aluminium film used to coat crisp packets, sweet wrappers and of course Tetra Pak. This is very effective in slowing vapour movement into the packet, greatly extending product shelf life. The aluminium is unlikely to be compatible with disposal by composting.  This is an issue that needs development. As production of biodegradable packaging is a tiny fraction of oil-based plastics, it is more expensive. This in part may be due to the small scale of production at less than 0.2% of the plastic packaging market. Like wind generators and solar panels, costs should fall as output increases.

How plastic can impede food waste disposal

Broccoli for example is often wrapped in clingfilm to minimise moisture loss. While the clingfilm is good for increasing its shelf life, this makes it unsuitable for feeding to cattle should it turn yellow. The plastic can choke cattle, so the load has either to be landfilled, burnt or sent to a composting or anaerobic digestion plant with plastics separation equipment. Far better to supply the broccoli in a reusable plastic tray, encased in a large plastic bag, which is cut open once the vegetable is on display. The bag can then be returned to the supplier to deal with.

London-Iona recycling test

When considering a recycling strategy, it is important to ask the questions “Can recycling be achieved as easily on the Island of Iona as in London?” If the answer is no, then we should consider other options. If we must rely on complex Materials Recycling Facilities (MRFs, pronounced Murfs), waste put in wheelie bins by householders in Iona have a long way to go to be recycled. In contrast wastes that can be composted can be treated locally either in local composting plant or in anaerobic digesters.

Recycling of oil based plastics in a state of flux

Reprocessing plastics is a daunting task

As of this year the Chinese are refusing to keep taking the UKs plastic waste. Until now this has been the preferred route for dealing with waste plastics as their labour costs for processing the waste are so low. The government now has an opportunity to decide on a future strategy for plastic packaging, so Uk industry can invest in confidence in plastic recycling equipment. The alternative is to find new low wage countries like India, Bangladesh or the Philippines that will process our waste, with environmental standards that may leave much to be desired.

Resistance to changes

The introduction of deposits on plastics bottles is likely to be opposed by retailers and drinks manufacturers. We the public presently subsidise their business, as in 2018, they are only required to retrieve 51% of the plastic packaging they produce.

Retailers protest about the additional space in their premises required by deposit systems. This should be treated with scepticism. If 1000 bottles are sold per day and 1000 returned per day, what additional storage, other than a sorting area is required?

Companies manufacturing oil based plastics may resist a move to biodegradable plastics and lobby government accordingly. However, government is increasingly aware of past campaigns by vested interests to “muddy the water”, so the industry would do well to be positive about an integrated strategy. With the scenario presented, there is plenty scope for oil based plastics to be used within the food industry’s internal orbit.

Recent developments

The recent cases of microbeads in cleansing products, cotton buds and drinking straws, all confirm the logic of moving away from oil-based plastics. Micro-beads are to be made instead from coconuts, apricot seeds, walnuts, bamboo and rice, all biodegradable. The suggested solution to cotton buds is to replace the plastic sticks with paper ones, so both cotton bud and stick are biodegradable. The plastics straws are to be discontinued and ones made of biodegradable paper sold instead.

Conclusion

In conclusion, the following actions should be taken by government.

Disposable coffee cups will be biodegradable and deposited in compost bins after use. A latte tax or various inducements will be introduced to get people to use reusable cups, thermos cups, etc. This will remove the waste coffee cup problem at source.

Retailers, including small stores and sweetie shops, would only sell oil based plastic bottles with deposits on them. (Cans and glass bottles would have similar deposits). Packaging from supermarkets, convenience stores, corner stores, DIY stores would all be biodegradable, either paper of biodegradable plastics.

Food and material movement within the orbit of stores, shops and the distribution network can use oil based packaging, but it must be returned to base for reuse, recycling or disposal.

Work will be required to bring biodegradable plastic packing to the level of extended shelf life that our present oil based plastics have.

These new measures should be phased in over a period sufficient to ensure that the change-over does not cause confusion. Once the policy is decided, this policy should be maintained, so that commerce has a firm assurance that the measures will become law at firm dates decided by government.

This new approach must be carried out in concert with our trading partners be they the EU or further afield. We need consistency to be effective.