Of all the memories I have of the pandemic last year, the image of bins sticks in my mind. Black bins piled high, green recycling bins stuffed with packaging from online deliveries and takeaways. Occasionally, I’d see a pizza box resting on top, as if whoever had left it was unsure where it could or should fit in. According to research, the amount of waste produced by each household in Britain rose by a fifth last year. But are we dealing with it in the right way? And where should that pizza box go?

I spoke to Adam Herriott, resource management specialist at Waste and Resources Action Programme (Wrap), a charity that focuses on recycling and the circular economy.

Putting the wrong thing in the wrong bin is known as ‘recycling contamination‘. Is it a problem?
It’s a big issue, because it only takes one person on your road to put rubbish in their recycling bin for the whole truckload to be rejected. Before I worked at Wrap, I was a recycling manager at a place where materials are separated, and our rejection rate was about 9% of vehicle loads.

That’s high. What sort of stuff were people putting in their bins?
All sorts. Firearms. Animals.

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I did not expect this conversation to take such a turn.
Mostly, it’s the stuff that should go in the regular bin. It’s important people don’t “wish-cycle” – where they are not sure but put it in anyway.

I’ve also heard it called ‘aspirational recycling‘, which makes it sound weirdly glamorous.
It happens all the time. People need to check with their council or use Recycle Now’s guide. Commingled bins used to be the thing, but segregated bins assure quality. If the paper and cardboard in your bin is kept clean and dry, it can easily be recycled, so it’s valuable.

Where does a pizza box fit? It’s not exactly clean.
It’s fine to be recycled as long as there’s no cheese stuck on the box, in which case, rip that bit off. It’s what we call “3D waste” – food and other solids – that’s the problem. And give containers a rinse. Wash and squash.

It’s probably not great that takeaway places switched to cardboard as part of the war on plastic if it ends up too soggy to be recycled.
We would never say one material is better than another. We just ask people and businesses to look at the bigger picture. Take compostable coffee-cup lids: if you don’t have a food waste bin or a home composting system, it will end up in the regular bin. Or sometimes people think it’s plastic. If compostables get in with the plastics, it can cause big problems.

This all sounds a bit high stakes. I thought this conversation would help my anxiety dreams.
One wrong thing in the recycling can be handled – it’s just when there’s too much of it. For example, people put nappies in because they’re papery, even though they’re full of …

3D waste.
Right. It can get everywhere in the back of a vehicle.

How did the pandemic change our recycling habits?
Everyone’s bins looked different. Mine was full of glass, until I switched to boxed wine. We’re waiting on the official data but, anecdotally, it sounds as if we recycled more, yes. But food on pizza boxes wasn’t a problem. I’d never waste good pizza.