Milk bottle tops and aerosol cans are not welcome in the recycle bin, but pizza boxes are fine - so long as the pizza has been removed.
New recycling rules came into effect at the start of February, standardising what is collected at the curb throughout New Zealand.
Checkpoint visited Palmerston North's Awapuni Resource Recovery Park for a peek behind the scenes and to see if people are abiding by the new rules.
The new rules include changes such as requiring people to remove lids from bottles - the bottles are recycled, the lids are not - and not collecting some types or numbers of plastic.
Palmerston North City Council waste minimisation officer Melissa Doyle said some people had not yet adapted to the changes.
"We are seeing a bit [items no longer collected] come through still. It takes a while for the public to catch on to the fact that we can't accept them any more."
Those items were now taken to the dump, although Doyle said Palmerston North was looking at options to recycle lids.
All is not lost if bottles arrive at the centre with their lids still on.
Palmerston North Recycle Facility team leader Tony Hanna said such bottles were still recycled.
"When the milk bottle goes up to the star sorter, that's enough to generally shake the lid up. It falls down and goes through the fines sorter, gets put into a bin and ends up getting dumped."
That star sorter plays a big part in Palmerston North's recycling operation.
About 20 tonnes a day of material comes into the recovery centre, which houses conveyer belts and about a dozen workers sorting through the things people chuck in their bins, in a mostly manual process.
The "bloody huge" industrial warehouse, where it all happens, is a couple of storeys high and is shared with a paper recycling company.
Out the back, a forklift driver pushes everything towards the conveyer belts, removing some of the obvious rubbish.
About 17 to 20 percent of what comes in cannot be recycled.
"A lot of it is an education thing, Some of it, unfortunately, people just think if they put it in the bin some pixies come along and make it magically disappear," Hanna said.
Palmerston North introduced some of the now-standardised national rules some time ago, so the likes of not having some plastics collected at the curb is not new to the city.
But plenty of rubbish still makes it to the recovery centre, and what the machines cannot pick out is removed by workers beavering away.
Some stand at the conveyer belt and have responsibility for one type of recyclable item - such as tin cans or plastics bottles - and separate this out as it goes past.
Hanna said the recycling changes would eventually bed in for people.
"It takes time to change habits and the reality is when you look at plastic it's plastic. You don't really think about what type of plastic it is, so that's an education thing.
"It will happen over time."
Doyle said there were plans to audit bins more closely from next year.
For now, she has a few tips for recyclers.
"Yes please, if you could give it a rinse. You don't have to scrub it with a brush and soap, but if you could rinse off the food that would be great."
If an unwashed item came in, it could still be recycled depending on how dirty it was.
"It's the same with pizza boxes. We want the cardboard box. We don't want the pizza. If you could take the pizza out.
"Little bits of grease and little bits of food are fine, but whole pieces of pizza? No thank you."
Centre workers make a few other finds.
"We get a few passports and licenses and keys. We found a cellphone in there once," Doyle said.
"Once someone rang up and said, 'I had an envelope of money and I think it's gone into the recycling, can you find it?'"
Unfortunately, it was not found.
There were also more unpleasant finds as well, with nappies often thrown into recycling bins, and even dead animals, although that was rare.
Doyle said that all recyclable material was turned into something - like bin liners and apple cartons.