I was recently asked some questions by a local resident about recycling. You may be interested in the responses which are set out below:

  1. We are told that only plastics of types 1, 2 & 4 can be recycled. Type 5 plastic is often used for dairy products such as yogurts. I am careful to try only to put recyclables into our green bin, but I’m sure a lot of people put anything that looks like plastic into theirs. How are the contents of green bins processed and how big a problem is it if the wrong types of plastic are in there?


The different plastic types reflect what types of chemical polymers have been used to create the material. The types of plastic (1,2 and 4) Leeds collects are based on what can be sold on the materials reprocessing market to be made in to new products. The plastic you put in the green bin is sent to our contractor’s material reprocessing facility in south Leeds. There the plastic is manually sorted from the other green bin material before being run through various machines that separate the 1,2 and 4 polymer types. The plastic is then flaked and washed. The polymers cannot be mixed due to the different chemical make-ups  meaning they melt and reform at different temperatures and consistency when being made into new products. If the plastic types are not high quality then they will be rejected by the materials reprocessing companies and cannot be recycled. Due to the market demand for high quality plastics, if you’re in doubt if it is 1,2 or 4 then please leave it out of the green bin.

2. Similarly, many wrappings, such as biscuit packets and gift wrap, are more like cellophane or foil than paper. Is it a problem if they are put in green bins?

Plastic wrappings such as biscuit wrappers and crisp packets  cannot be recycled in your green bin as it is not clear what type of plastic it contains. As such, this may cause poor quality plastic recylate that may be rejected by the material reprocessing companies. However plastic carrier bags are categorised as plastic film and although the market is fairly limited for this it can be recycled.

Paper can be recycled as long as it isn’t shredded and doesn’t have any additional coatings or foil additives on it. For example, wallpaper and wrapping paper. Again, it is about providing high quality materials that can be reprocessed and coatings or other additives are difficult to remove at the paper pulping mill. Shredded paper tends to jam the processing machines.

3. How big a problem is food contamination? I’m thinking of things like pizza and cake boxes that have been contaminated by their contents, plastic milk bottles and packaged meat containers that haven’t been rinsed out.

Food contamination contributes to poor quality recycling as it introduces waste materials in to the re-processing. This is exacerbated as the material collected in the green bin is compacted down by the refuse lorry to make room to  collect more material. We can accept materials like foil used for cooking and pizza boxes but the food residue must be removed.

We would encourage residents to give items a quick rinse or wipe down, so we can improve on the overall quality of secondary raw material we supply to the reprocessing markets.