Saturday, 9 July 2011

A personal proposal for controlling plastic trash - Part II

Friends, "luckily" I have been way to busy to report my ideas in this space on a frequent basis. I have just recently joined my former MRes supervisor to help him on a 2 months project regarding neurodegenerative diseases and protein aggregation after exposure to microwave radiation. It is a challenging project but I am one of those who thrive on challenges (that's what life should be all about anyway)! I will be working along with an Iranian researcher who has just arrived from Sweden where she completed her post-doc on... if I am not wrong... medical electro-physics! Is it right? I hope so hehe!, and I will also supervise a very young secondary school student on her Summer project. So, there is a lot of new adventures and experiences I'll be enjoying for the coming two months. In addition, I am still writing for Academic Knowledge, Ivory Research, interpreting in hospitals for The Big Word, Pearl Linguistics, and maintaining my role as freelance research assistant supporting masters and PhD students (at the time two of them) on their research projects. So, I have done well in keeping myself busy whilst trying to tackle unemployment by finding my way through opportunity.

But this post is about delivering the second part of my last post, concerning my personal proposal for managing and controlling plastic trash production. I promised I would bring to this space of ours the types of plastic that can and cannot be recycled, why that happens so and try and offer pertinent information from professionals who deal with this issue  regularly. I will try to approach all these subjects promptly and succinctly but it will be complicated as there is an immense field of info available. However, please do your best to read through the whole post as it does contain IMPORTANT information we should all be aware of: 

What plastics can be recycled?

All household plastic bottles and a variety of other mixed plastic containers can be recycled as long as they have not contained pesticides or motor oil. Recyclable mixed plastic containers include:

Yes please

  • Plastic household cleaner and detergent bottles
  • Plastic milk bottles
  • Plastic juice bottles
  • Plastic soft drink and water bottles
  • Plastic shampoo/shower gel bottles
  • Plastic food trays
  • Plastic yoghurt pots
  • Plastic margarine and ice-cream tubs
  • Plastic cups

No thanks

  • No plastic shopping bags or film
  • No crisp packets or sweet wrappers
  • No shrink or bubble wrap
  • No plastic toys
  • No polystyrene packing or beads
  • No CDs/DVDs or cases
  • No cable ties
  • No garden pots
Please rinse and squash containers before recycling them. This saves room in the recycling bins and on the collection lorries.

Why can't we recycle other plastics?

There are several reasons for this;
  • Market demand for mixed plastics (including bags and film) is currently limited and less secure. There is a strong market in the UK and Europe for mixed plastic containers.
  • To ensure value for money, councils are able to recycle more plastic per pound spent on the recycling scheme by collecting plastic containers only.
  • Collecting plastic containers only reduces contamination from different types of plastic and ensures high grade material that can be recycled.
  • Plastic containers are relatively dense and compact which enables them to be easily sorted mechanically, into the different types of plastics. Plastic film and bags are not easily mechanically sorted making them very costly to sort.
  • Plastic film and bags are much more likely to be contaminated with food waste and are difficult to clean.
Source: [1]

Why can I only recycle my plastic bottles?

Plastic bottles are specified as they are made from one of only three polymer types and are very easily identified, both by members of the public and those sorting the collected bottles. The three polymer types used are PET (e.g. fizzy drink bottles and squash bottles), HDPE (e.g. milk bottles and detergent bottles) and PVC (e.g. large squash bottles), although the use of PVC in such applications is in decline.

Items such as margarine tubs and rigid food containers are made from a very wide range of polymer, many of which are blends. These are much more difficult to identify and separate efficiently.

It is also more difficult to secure an outlet for the material as mixed plastics are not in high demand.
recycling plastics
Yoghurt pots
Yogurt pots are not generally accepted in plastic recycling schemes as they are in fact made from polystyrene. This has an entirely different make-up to the polymers used in bottles and there are currently limited outlets for the material. Again, there are fewer clearly identified end markets for the material at this time. The quality of the material is often compromised as a result of food contamination, making it necessary for householders to thoroughly wash the cartons before depositing for recycling.

In areas where yogurt pots and rigid food containers have been collected, the value of the material has been diminished by a lack of thorough cleaning.

Many people often enquire why they are advised to remove the lids from their plastic bottles when depositing them for recycling. The reason is, again, the lids are made from a different type of plastic to the bottle and, if mixed with the bottles, causes contamination of the polymer type, reducing both the quality and value of the material. This can have implications on the intended end-use of the recycled material due to the contamination's impact on end-product consistency.

Flower pots
Flower pots are another item about which questions are often asked. The majority of flower pots are made from polypropylene, (PP), although some are made from polystyrene. As in the case of rigid food containers and yogurt pots, there are few outlets for collected material and a higher level of contamination.

Carrier bags
Carrier bag recycling facilities are now available in some supermarkets. The facilities are not yet widespread due to the very lightweight nature of carrier bags and sale outlets are limited. The material is generally only used for low grade applications such as bin liners because of the contamination effect of the printing ink, making it only suitable for dark colours, such as grey or black.

Source: [2]

How are plastics recycled?

There are a number of ways plastics are recycled. Plastics can be:
Three very small clear plastics bottle full of a clear liquid.


Certain plastics can be reused, for example:
  • Plastic Drinks Bottles
  • Carrier Bags
  • Takeaway Containers


92% of all UK local authorities now offer collection facilities for plastic bottles either from your kerbside collection scheme or at recycling centres. 
What about other plastics?
WRAP has recently completed a study that has demonstated mixed plastics packaging (trays, tubs, pots, films etc) can be mechanically recycled and that it is both economically and environmentally effective to do so.  Further work is being conducted in this area and it is hoped that the UK will have comprehensive infrastructure for the collection, sorting and reprocessing of these valuable resources in the UK in the near future.
You can check the postcode locator to find out which plastics your local authority collects.

The process

Mechanical recycling is the process of recycling plastics by:
  • sorting;
  • shredding;
  • washing;
  • melting;
  • pelletise.
It is a two-stage process:
  • Sorting is mainly done automatically with a manual polish; 
  • Plastic is either melted down directly and moulded into a new shape, or shredded into flakes then melted down before being processed into granulates

Source: [3]

Why should we bother?

The world's annual consumption of plastic materials has increased from around 5 million tonnes in the 1950s to nearly 100 million tonnes today.

We produce and use 20 times more plastic today than we did 50 years ago!

In the UK, a total of approximately 4.7 million tonnes of plastic products were used in various economic sectors in 2001.

Uses of plastic

Packaging represents the largest single sector of plastics use in the UK. The sector accounts for 35% of UK plastics consumption and plastic is the material of choice in nearly half of all packaged goods. (seepackaging information sheet for further information).
Uses of plastic as percentage

Plastics consumption is growing about 4% every year in western Europe.

Plastics makes up around 7% of the average household dustbin.

Plastic as a percentage of household waste
Source:Analysis of household waste composition and factors driving waste increases - Dr. J. Parfitt, WRAP, December 2002

The amount of plastic waste generated annually in the UK is estimated to be nearly 3 million tonnes. An estimated 56% of all plastics waste is used packaging, three-quarters of which is from households. It is estimated that only 7% of total plastic waste arisings are currently being recycled.

The production and use of plastics has a range of environmental impacts. Firstly, plastics production requires significant quantities of resources, primarily fossil fuels, both as a raw material and to deliver energy for the manufacturing process. It is estimated that 4% of the world's annual oil production is used as a feedstock for plastics production and an additional 3-4% during manufacture.

A report on the production of carrier bags made from recycled rather than virgin polythene concluded that the use of recycled plastic resulted in the following environmental benefits:

  • reduction of energy consumption by two-thirds
  • production of only a third of the sulphur dioxide and half of the nitrous oxide
  • reduction of water usage by nearly 90%
  • reduction of carbon dioxide generation by two-and-a-half times

A different study concluded that 1.8 tonnes of oil are saved for every tonne of recycled polythene produced.

In addition, plastics manufacture requires other resources such as land and water and produces waste and emissions. The overall environmental impact varies according to the type of plastic and the production method employed.

Plastics production also involves the use of potentially harmful chemicals, which are added as stabilisers or colorants. Many of these have not undergone environmental risk assessment and their impact on human health and the environment is currently uncertain. An example of this is phthalates, which are used in the manufacture of PVC. PVC has in the past been used in toys for young children and there has been concern that phthalates may be released when these toys are sucked (come into contact with saliva). Risk assessments of the effects of phthalates on the environment are currently being carried out.

The disposal of plastics products also contributes significantly to their environmental impact. Because most plastics are non-degradable, they take a long time to break down, possibly up to hundreds of years - although no-one knows for certain as plastics haven't existed for long enough - when they are landfilled. With more and more plastics products, particularly plastics packaging, being disposed of soon after their purchase, the landfill space required by plastics waste is a growing concern.

Plastic waste, such as plastic bags, often becomes litter. For example, nearly 57% of litter found on beaches in 2003 was plastic.

Source: [4]

What else should I know?

It takes 25 two litre plastic drinks bottles to make one fleece garment.

A note regarding plastic bottle top collections: At present we are aware of only two collectors that will accept plastic milk-bottle tops for cash. If you believe you know of a scheme collecting for wheelchairs or other causes or cash, contact them directly to make 100% certain that they are willing to take bottle tops. The money that can be raised through plastic bottle top collections is small and it may be more worthwhile to collect cans, mobile phones or printer cartridges. If you have already collected a large number of bottle tops then it may be possible to find a reprocessor using the search facility on

Every year, an estimated 17½ billion plastic bags are given away by supermarkets. This is equivalent to over 290 bags for every person in the UK.

That's it for today, and what a long post. I know this time I had to use a lot of external information but the sources I used are very professional and know how to build proper awareness on such a ever growing issue. Please visit the links I provided, especially source 4 that does contain fantastic information about recycling with very good in-depth, insight and data. Anytime soon I will be writing about bioplastics... anytime soon, but next week we will all laugh and smoke with The Toxicologist Today as Sheesha, Narguile and the like will puff the magic dragon in this space.

See you soon!

[1] - London Borough of Richmond Upon Thames, What plastics can be recycled?,

[2] - Recycling specifics,, Last visited on the 09th of July 2011, last update unknown.

[3] - Recycle now, Can it be recycled?,, last visted on the 09th of July 2011, last update unknown

 [4] - Waste Online, Plastic information sheet,, last visted on the 09th of July 2011, last updated on February 2006.

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