Commonly confused non-recyclable items



17 December 2020


During bin audits, contractor Waste Watchers Ltd pointed out some common recycling contaminants in the kerbside recycling service in Rotorua.

The audits started with staff randomly selecting rubbish and recycling bins, and emptying their contents into separate plastic bags. Once they collected a sample of around 700kg of waste, they returned to the Recycling Centre.

They weighed each bag, sorted the rubbish into 23 categories, and sorted the recycling into 14 categories. Each category is weighed and recorded. Waste Watchers staff repeated this each morning of the 5 day audit.

In the recycling sample, all non-recyclable items are divided by their material type; Non-recyclable paper, plastic bags/film, other non-recyclable plastics, non-recyclable glass, bagged rubbish and other materials.

These items are not supposed to be put in the recycling bin and are considered 'contaminants'. They could make clean recyclable items dirty (and no longer able to be recycled), or impact the value of the collected recycling.

Reducing the level of contamination in recycling streams helps to lower the cost of recycling for the city and maximise the amount of recyclables that can be turned into new items. The more items that are correctly recycled, the less that are unnecessarily sent to landfill.

Here are some items that are often confused as being recyclable, but should go into the red lid rubbish bin;

  • Tetrapak containers are often used for long life milk, juice or stock. The containers are made from a combination of cardboard and plastic that cannot be easily separated.

  • Soft plastic packaging needs to be removed and put into the rubbish bin before any cardboard goes into the recycling.

  • Re-usable material bags cannot be recycled through the kerbside service.


  • Biodegradable items (e.g. takeaway containers) need to go into the red lid rubbish bin. Some of these items can be put into composting systems, but you need to check the instructions first (often found on the bottom of the item).


  • Soft plastics such as bubble wrap, Glad Wrap, bread bags or shopping bags should not go into the kerbside recycling service. However, some supermarkets offer soft plastics collection to be recycled.

  • Pet food bags are commonly made of a combination of cardboard and plastic. These materials cannot be separated easily, and need to go into the rubbish. 

  • Some re-usable containers are not made of recyclable plastic. To check if it is recyclable, look on the item for a triangle plastic identification symbol with the numbers 1,2 or 5. If there are numbers 3,4,6 or 7, or no plastic identification symbol, put it in your rubbish bin.

  • All food waste needs to be emptied and cleaned from recycling items before it is put in the recycling bin.


Why is contamination a problem?

The higher the level of recycling contamination, the lower the value of the collected recycling as there is more work needed to sort and separate it at Materials Recovery Facilities.

The more contaminated recycled items are, the less they can be successfully recycled and may end up in landfill.

On-selling the collected recycling contributes to lowering the cost of the recycling service for Rotorua, and therefore lowers the total cost of the recycling service for the district.


How do I know what is able to go into the kerbside recycling service?

Items that can go into the recycling bin must be clean and dry;

  • Paper and cardboard
  • Newspaper and magazines​
  • ​Aluminium and tin cans​
  • Plastics numbered 1 – 7
    (Please note: Next year we will be aligning with national recycling standards, and accepting plastics 1,2 and 5 only.)

You can find more info about what should not go into the kerbside recycling bin here.


Where can I find out more about this year’s bin audit, and what it means?

Read more here.


For more information on the kerbside rubbish and recycling service, click here.

Page reviewed: 17 Dec 2020 4:59pm