"Unfortunately, not all clear plastics are labelled number 1. Some are now labelled number 3, 5 or number 6. Therefore they are not PET plastic," she said.
The clear plastics can look much the same, and people recycling at the centre have been putting containers in the wrong places. She's asking people to check the numbers and get it right.
If they are confused, they can ask the helpful staff.
PET (polyethylene terephthalate) plastic is the most used packaging material in the world. Flight Plastics makes it into containers for berries, bakery goods and meat.
Its containers are 60 to 88 per cent recycled plastic, with a thin coating of new plastic on the outside for food safety. The plastic can be used again and again.
The containers it makes have the words "Flight New Zealand recycled plastic" stamped on them, with the number 1.
New Zealand has been importing 20,000 tonnes of PET a year for food containers, Flight Plastics director Derek Lander said.
The Lower Hutt factory can process 6000 to 8000 tonnes a year, reducing the amount being imported and the amount going to landfill.
The WRRC wants to support that. It's getting more precise about other plastics too, and now has separate slots for Meadowfresh, Anchor and other milk bottles.
It sends polypropylene and high density polyethylene plastic to Palmerston North, where it is made into granules used to make compost and wheelie bins.
The WRRC has to find new markets within New Zealand for recyclable plastic, because China is no longer taking most of it.
"As members of the Zero Waste Network we are committed to searching for environmentally sustainable solutions," Te Uamairangi said.