How to recycle mixed plastics in the UK

How to recycle mixed plastics in the UKAsk anyone what the bane of their zero waste lifestyle is and 90% of people will say something to do with plastics.

When we started our zero waste journey we only had access to glass, tins and paper recycling at the kerbside.

Over the years our kerbside collections have increased to include cardboard, garden waste, food waste, textiles and plastic bottles.

The plastic bottles, while really handy for us, is still very confusing.

I’ve been reading up on the various types of plastics available. While there are over 50 different types available, six common types have been given codes which help identify them for recycling. There is a seventh category for “other” plastics:


Some are easier to recycle than others which makes the whole plastics recycling industry a bit of a minefield for the average householder to understand.

Recycling plastic drinks bottles

For example, PET – often used for drinks bottles – is a high quality product which can be recycled into polyester fibre to make sports fleeces or carpets.

So far so good.

But then come the ubiquitous black plastic trays, typically used for convenience meals. Even though the four trays I have sitting here at Zero Waste Towers are marked as PET, they cannot be recycled anywhere. The reason for this, say WRAP, is that the majority of black plastic packaging is coloured using carbon black pigments – these are not able to be sorted by the optical sorting systems being used widely in plastics recycling. As a result, black plastic packaging commonly ends up as residue and is disposed of in landfill or recycled into lower value materials where polymer sorting is not required.

Which begs the questions – Why are manufacturers still using black plastic trays for their products and, in this age of technological advances, why haven’t we developed Optical Sorting Systems that can deal with black plastics? I’m assuming the conveyor belt is black, so perhaps we could change them to fluorescent yellow or something!

Recycling plastic milk bottles and their caps

HDPE, often used for milk cartons and the caps of bottles is another high quality product which can be chopped, washed and converted into flakes or pellets. According to a sustainability expert on Quora, HDPE recycling is more cost-effective than PET, because recyclers can earn more by selling recycled HDPE pellets.

I’ve noticed that while a drinks bottle might be PET, the caps are mostly coloured and made from a HDPE. I’m assuming then, that local authorities who take bottles with lids are doing co-mingled collections. Whereas local authorities which ask householders to remove lids are collecting a better quality recyclate? I’m wondering if the local authorities that collect bottles with lids on are ‘downcycling’ into a mixed plastic or whether they have the technology to separate bottles and caps. Perhaps some friendly local authority will get in touch and explain things to me.

Recycling plastic bottles

My local authority recycles ‘plastic bottles’ at kerbside. When I queried them, it literally means anything bottle shaped. Whether that is from a clear bottle of water or washing up liquid, a blue bottle of shampoo or a yellow bottle of bleach, it doesn’t matter. If it’s bottle shaped and it’s plastic, I can recycle it from my kerbside. Picking up some bottles at random here at Zero Waste Towers, I’m faced with a lot of PET and HDPE, as expected, but also some PP and unmarked items. Again it begs the question – is this going to be ‘downcycled’ into ‘mixed plastics’ or will it be sorted somewhere?

Plastic Film

Film is the type of plastic that causes most householders frustration. The British Plastics Federation say that 20% of local authorities collect plastic film from kerbside. Although, when questioning members of my Facebook Group, it was nearer 8%. Products made from recycled films include refuse sacks, damp-proof membranes, garden furniture and fencing.

Mixed plastics recycling

A friend of ours lives half a mile away from his recycling centre and they take the following:


I visit him once a week so have saved up some yogurt pots to take. Two more friends heard about this and I offered to take their items in too. It was fascinating going through these items and putting them into plastic types. A sizeable chunk of the items were not marked at all and I discovered that currently there is no mandatory requirement for manufacturers to mark plastics; it’s all voluntary!

different plastic polymer recycling codes zero waste week

Then I discovered that one of my friends had an assortment of different colour plastics – brown and green fruit and vegetable punnets and purple pots of chocolatey loveliness for the kids. All of these were PP. When I look at the guidance above from the recycling site I’m going to visit this week, it doesn’t actually say anything about the colour of anything, unless it’s one of those black-coloured trays. Maybe I’m completely missing the point and the colour of the plastic isn’t important. One thing is for sure – I’m hoping there is someone knowledgeable and willing to talk to me when I visit the recycling centre so I can truly begin to understand the situation of mixed plastics recycling in the UK!

recycling mixed plastics with different codes zero waste week

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Rachelle Strauss


  1. Max Williams on November 9, 2017 at 8:28 pm

    I work as a cleaner at the university of York and recycle as much of the rubbish that I collect as I can. The recycling policy of the university is more encouraging than the council, but there is far too much that goes to landfill. It would be more radical and appropriate to the desperate times in which we live to aim for zero waste at the university. Do you think that it is possible?

    • Rachelle Strauss on November 10, 2017 at 5:14 pm

      Hi Max, I believe it’s possible, yes (ever the optimist, me!). It would take committed and caring individuals like yourselves to form an action group or committee with the support of the decision makers. Your best bet would be to complete a waste audit, then set out a plan over the next few years to reduce landfill waste to zero. It’s a win-win because there is nearly always money to be saved as well.

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