No matter how many times you put them in the bin, lids still can’t be recycled.

Despite the government’s valiant efforts to make recycling completely consistent throughout the country, and The Spinoff’s valiant (if we do say so ourselves) efforts to keep explaining what is going on with our waste system, there’s still widespread confusion about recycling. What goes in what bin? What are the rules about lids? 

Five months after the new rules came in, the recycling sector is still reporting that contamination is high: lots of stuff that can be recycled is going to landfill, and lots of stuff that can’t be recycled is ending up at the recycling plant. Recycling the wrong stuff (or contaminating otherwise recyclable items with gunk) is bad for everyone: it makes recycling less efficient and more expensive, contaminates the efforts of people who did rinse their milk bottles and take the lids off, and makes recycling worker’s job harder. Here’s quick explainer for next time you’re hovering over the bin with a lid in your hand, wondering where it should go. 

Lids! Lids! Are you really sure I can’t recycle lids? 

There has been a lot of confusion around this at The Spinoff offices, but the truth is that no lid of any size should go in your recycling bin – even big ones, like ice cream container lids. The rule of thumb for general recycling is that if something is smaller than 5cm x 5cm, it can’t be recycled, but when it comes to lids, their thinness means they can still fall through the machinery at recycling centres even if they’re bigger than 5cm. If they’re still attached to the bottle or container, they can reduce the quality of recycled material due to being made out of a different type of plastic. There are some alternatives – for example, in Wellington the Sustainability Trust has a free drop-off service for plastic and metal lids, and Auckland Council allows you to search to find where you can drop off stuff that can’t go in the recycling bin. 

So just to be clear once and for all. You cannot recycle any lids.

What else can I not recycle? 

The obvious stuff: food, garden waste, plastic that isn’t 1, 2 and 5, chemicals, batteries, building materials, nappies and sanitary waste. 

But also some of the non-obvious stuff: glass from beverage bottles is recyclable, but other kinds of glass, like from mirrors, windows, lightbulbs, cooking utensils or drinking glasses can’t be recycled. Really big plastic containers that are more than four litres can’t be recycled. Aluminium drink cans can be recycled, but gas canisters can’t. 

I’m also still confused about pizza boxes. Does the grease gum up the recycling system? What about when the stuff to recycle has food on it?

While you should definitely rinse or scrape food off your recycling if you can, it doesn’t have to be perfect; recycling systems can handle pizza boxes that are greasy as long as the food is out. Shake your sauce or juice bottles with a bit of water to remove the detritus, swish the dish brush around the hummus container, flick out the pizza crumbs – and then put the packaging in the recycling. As a bonus, clean recycling is much less likely to attract insects and rats to the bins.

Why are there so many kinds of plastic that can’t be recycled? 

Plastic is made from oil, which is why promoting its use (including recycling), works in the oil industry’s favour. About 10% of plastic that has ever been made has been recycled, because making new plastic often works out cheaper, and only 1% has been recycled more than once. China used to accept many rich countries’ plastic, including New Zealand’s, but it stopped because much of the plastic was too contaminated to be valuable. This meant that there were fewer kinds of plastic that could be processed in New Zealand – part of the reason that soft plastic bins that used to be common in supermarkets are slightly harder to find now. 

Beyond that, lots of plastic is made to be stable: hard, set in shape, light and strong. The qualities that make it so convenient is what makes many kinds of plastic difficult to recycle: the long polymer chains get shorter each time they are melted and formed into a new material, becoming a lower quality substance. Additionally, lots of plastics contain dyes and other chemical additives that can react unpredictably when mixed with each other. Often recycled plastic is mixed with new plastic to create recycled plastic items – although there are always enthusiastically heralded new technologies coming through that promise to change this.

How does recycling in New Zealand compare to other places? 

In a comprehensive 2023 Waste Strategy from the Ministry for the Environment, New Zealand’s reuse and recycling rates are described as “poor” compared to other countries. On average, each New Zealander is estimated to have generated 700kg of waste that ended up in landfills in 2021, meaning that New Zealand is one of the highest waste producers in the OECD. There isn’t always a market for recycled materials (partially due to our small size), and while many in the waste sector try innovative new things like turning plastics into plasterboard, others say that this is just “distributing a landfill full of rubbishy plastic bags around the country”. 

New Zealand is part of a global plastics treaty intended to reduce plastic waste and pollution, which is expected to be negotiated by the end of this year. We also have a National Plastics Action Plan, and a bevy of other strategies, goals, commitments and projects led by central government, local government and the waste sector – which simplifying the recycling rules was intended to help with. 

Reducing plastics and embracing the “circular economy” in New Zealand is part of a global effort that will require redesigning many aspects of modern life that assume that plastic will always be cheap and plentiful. As the recycling blogs love to point out, the “five Rs” are a hierarchy: refuse stuff that produces rubbish, reduce the waste you generate, reuse what you can, repurpose what you can’t – and then recycle.

Why is recycling so confusing? 

If I knew that, I wouldn’t have had to write this article. 

This piece has been amended to add further clarification around lids.